Sum - The result of addition
Difference - The result of subtraction
Product - The result of multiplication
Quotient - The result of division
Term - A value that is either a coefficient or variable, or a product of multiple
Like Terms - Terms that are exactly the same except for possible their coefficients
Algebraic Expression - A term or terms connected with algebraic operations (adding, subtracting, multiplying, etc.) and/or grouping symbols (brackets, roots, etc.)
Equation - A statement that the values of two expressions are equal, indicated by the symbol =
Simplify - Combine like terms and factors. Remove brackets and grouping symbols. Reduce. Rationalize the denominator. Evaluate exactly. Write fractions as mixed numbers. Write with only positive exponents. State restrictions and variables.
Evaluate - To solve using a certain method
Solve - To find all the values of the variables that make the equation true
Factor, v. - To rewrite as a product
Factor, n. - A divisor; numbers/polynomials that are multiplied together to form an expression
Relation - A connection/correspondance between the values of two variables
Function - A special relation that connects each value of the independent variable to exactly one value of the dependent variable
Domain - The set of all possible values for the independent variable
Range - The set of all possible values for the independent variable
Natural Numbers - N : Any number in the sequence 1, 2, 3, ... ; commonly referred to as the counting numbers
Whole Numbers - W : Any number in the sequence 0, 1, 2, ...; all natural numbers as well as zero. They are the answers to the question "How many?"
Integers - Z : Any number in the sequence ... -3, -2, -1, 0, 1, 2, 3, ... ; all of the whole numbers and their opposites
Rational Numbers - Q : Any number that can be written as a ratio (fraction) of two integers; any number that when written in decimal form has a terminating or repeating decimal
Irrational Numbers - Q' : Any number that can NOT be written as a ratio (fraction) of two integers; any number that when written in decimal form has a non-terminating and non-repeating decimal.
Real Numbers - R : All rational and irrational numbers
X-Intercepts - The point(s) where a graph intersects the x-axis (when y=0)
Y-Intercepts - The point(s) where a graph intersects the y-axis (when x=0)
Commutative Property of Addition - a + b = b + a
Commutative Property of Multiplication - ab = ba
Associative Property of Addition - a + (b + c) = (a + b) + c
Associative Property of Multiplication - a(bc) = (ab)c
Distributive Property - a(b + c) = ab + ac
Zero Property of Multiplication - (a)(0) = 0
Inadmissible - Values that cannot be used
Absolute Value - The distance from zero on a number line (always positive), shown by | |
Opposites - Two values with the same absolute value but different signs
Reciprocals - Two numbers whose product is 1. One value is equivalent to 1 over the the other value
Translation - A transformation that causes all points on a graph to move the same amount in the same direction, which produces a congruent image in the same orientation
Dilation - Stretches or shrinks that change the shape of the original graph by moving values closer or farther from zero
Reflection - Transformations that move points to the opposite side of zero and may change the orientation
Invariant Point - A point that is not affected by a transformation
Asymptote - A line that a graph approaches but never crosses
Axis of Symmetry - The line on a graph where both sides are symmetrical
Inverse of a Function - Another relation that still connects the same two variables but reverses the mappings of the original function.
One-to-One Function - If different inputs always produce different outputs, and inputs can only be the same if outputs are the same
Increasing Function - A graph where x gets bigger as y gets bigger, or as x gets smaller, y gets smaller
Decreasing Function - A graph where x gets bigger as y gets smaller, or as x gets smaller, y gets bigger
Argument of a Function - The value that is inputted
Odd Function - A function where every point in the domain has a mirror point with opposite x and y-values. f(-x) = -f(x)
Even Function - A function with every point in the domain having a mirror point with an opposite x-value. f(x) = f(-x)
Index - The root which is being taken
Radicand - The number of which the root is taken
Base - The number which is being multiplied by itself
Exponent - The number of times that a number is multiplied by itself
Linear Growth - A value that increases by a constant difference
Linear Decay - A value that decreases by a constant difference
Exponential Growth - A long period of relatively little change followed by explosive, exponential growth
Exponential Decay - Dramatic, exponential decreases followed by a long period of relatively little change
Half-Life - The amount of time it takes to end up with half of the starting amount
Doubling Time - The amount of time it takes to end up with double the starting amount
Hypotenuse - The long side of a right triangle
Legs - The two sides adjacent to the hypotenuse and right angle
Ratio - The relationship in quantity between two values
Angle - An amount of rotation around a point called the vertex
Initial Arm - Where the rotation starts. On the positive x-axis for standard position
Terminal Arm - Where the rotation ends
Coterminal Angles - Angles with measures that differ by a multiple of 360∘ or 2π. In standard position, coterminal angles have the same terminal arm
Reference Angle - The acute angle between the terminal arm and the x-axis
Special Angle - Angles in trigonometry that can be expressed as an exact value of its ratio
Sine Ratio - y/r
Cosine Ratio - x/r
Tangent Ratio - y/x
Cosecant Ratio - r/y
Secant Ratio - r/x
Cotangent Ratio - x/y
Angle in Standard Position - An angle that has its vertex at the origin and its initial arm on the positive x-axis
Identity - Equations that are true for every value of the variable(s) for which they are defined
Periodic Function - A function whose values repeat at set intervals of the independent variable values
Period of a Function - The horizontal length of one cycle of a periodic function
Amplitude - Half the vertical distance from the max to the min of a periodic function
Sinusoidal Function - A function that repeats in a smooth wave pattern
Phase Shift - A horizontal shift of a periodic function
Principal Amount - The amount of money initially invested
Interest - The amount of money earned by an investment/paid on a loan
Accrued Amount - The total of the original principal plus interest
Present Value - The amount of money initially invested or borrowed
Future Value - The total of the original principal amount plus interest
Simple Interest - Interest earned/paid on the original principle only
Compound Interest - Interest earned/paid on both the original principle and any previously earned interest
Compounding Period - The amount of time that passes before interest is compounded
Always try to common factor first
A number with factors of one and itself are prime
Sum of Two Cubes - a³+b³= (a + b)(a² - ab + b²)
Difference of Two Squares - a²-b² = (a + b)(a - b)
Difference of Two Cubes - a³- b³ = (a - b)(a² + ab + b²)
Perfect Square Trinomial - (a + b)² = a² + 2ab + b²
Decomposition - ax² + bx + c = ax² + mx + bx + c
Where mx + nx = bx, and (mx)(nx) = (ax²)(c)
nth root - a number c is the nth root of a if cn = a, or n√a = c
Even roots - the radicand cannot be negative, or else there are no real numbers
When taking the even root of a positive radicand, there is a negative and positive root
If there is no ± sign, it is assumed to be the principal root (non-negative roots only)
Odd roots - the root will have the same sign as the radicand, and only one possible root
Properties of radicals
even n, n√an = |n| | (n√a)(n√b) = n√ab | n√am = (n√a)m |
odd n, n√an = n | n√(a/b) = (n√a)/(n√b), b≠0 | *n = the nth root being taken |
Reducing radicals
Break a single radical into two radicals, one of which can be evaluated
The radicand should not contain any factors that have degrees greater than or equal to the index
Adding/subtracting
Combine like terms
Multiplying/dividing
If they have the same indices, multiple the radicands and combine
Rationalizing the denominator
Monomial denominator - multiply the top and bottom by just the square root
Binomial denominator - multiply the top and bottom by the denominator’s conjugate
and - both must be true; or - at least one must be true
To check if two are equal, simplify both and check if they are exactly the same
Multiplying or dividing
For division, multiply by the reciprocal
Factor the numerator and denominator
Cancel common factors
Consider opposites - a negative 1 can be factored out to make them equal
Multiply numerators and denominators
State all restrictions based on the original expression using AND
For division, consider the numerator and denominator of the second factor
Adding or subtracting
Factor each numerator and denominator
Reduce each individually
Compare the denominators - multiply the fractions by terms that are not common
Add or subtract
For subtracting, be sure to apply the negative to the whole numerator
Reduce
State restrictions
|m| is the absolute value and a grouping symbol, so they should be treated like brackets
|m| = m if m is non-negative
|m| = -m if m is negative
|m| = -m if m is non-negative, there are no solutions
Properties of absolute values
|a| = |-a| | |ab| = (|a|)(|b|) |
|a/b| = |a|/|b|, b ≠ 0 | |a + b| ≤ |a| + |b| |
Solving linear absolute values
Isolate the absolute value
Break it into two equations
Solve each equation
x and f(x) or y are used to represent relations with no context
In a function, one input will always produce one output
If independent values repeat, it is not a function
If more than one arrow goes from one independent value, it is not a function
On a graph, if a vertical line drawn at any point can intercept more than one point, it is not a function
Explain the points that can be intercepted, what this says about x-coordinates, and conclude if it is not a function
In an equation, isolate the dependent variable - if the independent variable can produce more than one result (ex. even roots, absolute value), then it is not a function
Function notation: f(x) is “f of x” or “f at x”
If a ≠ b, f(a) ≠ f(b)
If f(a) = f(b), then a = b
Neither the input or output can repeat
Must be a function that does not produce repeating dependent variables
On a graph, use a horizontal line test if it passes the vertical line test
Solving one-to-one functions algebraically, if x-values aren’t known
“If f(a) = f(b)”
Use the formula for f(x) to substitute in (a) and (b)
Isolate a, and show each step
If a = b, this is one-to-one, and if a ≠ b, it is not one-to one
Conclude: “When f(a) = f(b), the conclusion is that [a = b] or [a ≠ b]. Therefore, f(x) is [not] one-to-one.”
Solving one-to-one functions algebraically, if two known inequal x-values produce different y’s
“If f(a) = f(b):”
Input each of the x-values
Isolate for each individually
Conclude: “a ≠ b, but f(a) = f(b). Therefore, f(x) is not one-to-one.”
Name | Principle Root | Absolute Value | Reciprocal |
Formula | y = √x | y = |x| | y = 1/x |
Domain | {x∈R|x≥0} | {x∈R} | {x∈R|x≠0} |
Range | {y∈R} | {y∈R|y≥0} | {y∈R|y≠0} |
Max/Min | Minimum of 0 | Minimum of 0 | None |
Named points | Endpoint at (0,0) | Corner at (0,0) | None |
Asymptotes | None | None | Vertical: x = 0 Horizontal: y = 0 |
One-to-One? | Yes | No | Yes |
Odd/even/neither | Neither | Even | Odd |
Intervals of increase or decrease | Always increasing | Increase when x≤0 Increase when x≥0 | Decrease when x<0 Decrease when x>0 |
R.A.P’s | (0,0), (1/4,1/2) and all points where x is a perfect square whole number | (0,0), and one point far out on each arm | Asymptotes; All easy to locate points until they are one line or closer to an asymptote |
Mapping formula | y = a[√k(x-h)] + v | y = a|k(x-h)| + v | y = a/[k(x-h)] + v |
Mapped coordinates | [ay + v, (1/k)x + h] | [ay + v, (1/k)x + h] | [ay + v, (1/k)x + h] |
Increasing function: when x1 > x2, f(x1) > f(x2)
Increasing function: when x1 > x2, f(x1) < f(x2)
Input values from the domain
Even functions are symmetrical along the y-axis
Odd functions are the same when rotated 180∘ around the origin
To solve algebraically:
Simplify f(x) and f(-x)
Compare f(-x) and f(x). If they are equal, it is an even function
Conclude that “f(x) =/≠ f(-x). Therefore, this is [not] even.”
Find -f(x), simplify it, and compare it to f(x). If they are equal, it is odd.
Conclude that “f(x) =/≠ -f(x). Therefore, this is [not] odd.”
If it is neither odd nor even, it is neither
When the mappings (independent and dependent) are reversed
The range of a function becomes the domain of the inverse, and vice versa
Inverse of a function is not always an inverse function (occurs in one-to-one functions)
Graphs are flipped across the line y = x
Pick key anchor points and swap their coordinates
Solving given context:
Write the function’s formula
Isolate for the independent variable, making it now the dependent
Considering the equation and context, decide the inverse domain and range
The values of the domain of the function will have the same values in the inverse, but instead as the range, and vice versa
In some cases, values may only be non-negative, so input 0 into the equation and solve for the restriction
Input any values to solve
Solving without context:
Swap the x’s and y’s
Isolate for y
Algebraic test for inverses
f(x) and g(x) are inverses iff f(g(x)) = x and g(f(x)) = x
Input one equation into the other and simplify
If both equal x, conclude that they are inverses
y = f(x - h) + v → (x + h, y + v)
All x’s are replaced with x - h, and a horizontal shift of h units occurs
h will appear as its opposite in the equation, so shift it the opposite direction
v is added to all y-coordinates, and a vertical shift of v units occurs
Alter the points from the parent formula, or plot the point of reference (h, v) and plot the parent function as if it were the origin
y = af(kx) → [(1/k)x, ay]
Graphs are horizontally stretched or shrunk by |1/k|, and may be reflected
Graphs are vertically stretched or shrunk by |a|, and may be reflected
Graphs are stretched by a factor > 1
Graphs are shrunk by a factor < 1
y = af[k(x - h)] + v → [(1/k)x + h, ay + v]
y = af[kx - kh)] + v → [(1/k)(x + kh), ay + v]
When stating horizontal transformations:
If the argument is factored, state dilations first, then shifts
If the argument is not factored, state shifts first, then dilations
Vertical transformations affect the function as a whole
Horizontal transformations use the opposite operations
Creating accurate sketches:
Determine the point of reference
Factor the argument if necessary
Apply reflections and dilations only to the parent points
When giving equivalent formulas, consider fractions, factoring the argument (or not), separating and evaluating radicals, etc.
Product Rule (bm)(bn) = bm+n | Quotient Rule bm/bn = bm-n | Power of a Power (bm)n = bmn | Power of a product (ab)m = ambm |
Power of a Quotient (a/b)m = am/bm | Zero Exponent Rule bm = 1, b≠0 | Negative Exponent Rule b-m = 1/bm, b≠0 | Rational Exponent Rule bm/n = n√bm n∈N |
If the base is a constant, work in radical form
If the base is a variable, work in exponential form
The exponent only applies to the factor that they directly follow
logba is “logarithm base b of a,” where b is the base and a is the argument
y = logbx iff by = x, b > 0, and b ≠ 1
y = logbx is in logarithmic form
by = x is in exponential form
logbx is the exponent that must be applied to b to get a value of x
If the base is not written, the convention is that it is 10 (common logarithms)
If the base is e, it is a natural logarithm written as ln
Logarithm of a Power logaax = x logaa = 1 | Power whose exponent is a log alogax = x | Product Rule logamn = logam + logan Must have the same base and a coefficient of 1 |
Quotient Rule loga(m/n) = logam - logan Must have the same base and a coefficient of 1 | Power Rule logaxm = (m) logax | Change of Base Rule logax = logmx/logma m can be any positive base that is not 1 |
Formulas that match f(x) = bx, b > 0, and b ≠ 1
Consecutive values of the finite differences change by a constant factor (excluding 1, 0, -1). This means that the ratios of every pair of consecutive finite differences are the same
The formula for the function has the independent variable in the exponent of a power with a constant base
Long periods of almost no change in the function values, followed by faster and faster increase or decrease
Name | Exponential Growth | Exponential Decay |
Formula | f(x) = bx, where b>1 | f(x) = bx, where 0<b<1 |
Domain | {x∈R} | {x∈R} |
Range | {y∈R|y>0} | {y∈R|y>0} |
X-intercepts | None | None |
Y-intercepts | y = 1 | y = 1 |
Max/Min | None | None |
Named points | None | None |
Asymptotes | y = 0 | y = 0 |
One-to-One? | Yes | Yes |
Odd/even/neither | Neither | Neither |
Intervals of increase or decrease | Always increasing | Always decreasing |
R.A.P’s | Plot the asymptote, with at lease one positive and one negative x integer, and continue without touching the asymptote | Plot the asymptote, with at lease one positive and one negative x integer, and continue without touching the asymptote |
Mapping formula | f(x) = abk(x-h) + v | f(x) = abk(x-h) + v |
Mapped coordinates | (af(x) + v, (1/k)x + h) | (af(x) + v, (1/k)x + h) |
Strategy 1: A single power on each side with the same base
The exponents must be equal
Strategy 2: Convert an exponential equation into a logarithmic equation
Strategy 3: Take logarithms using the same base of both sides, and then use the power rule for logarithms
To change by a constant factor
Exponential growth is little change followed by explosive growth
Exponential decay is characterized by a dramatic decrease followed by a long period of relatively little change
In a word problem, the first factor will usually be the base, the second factor will be the base multiplied by the constant factor to the first exponent, and then the exponent will continue to grow
To solve:
Establish that it is exponential
Use Ac = AIFt/p
Ac = Current Amount
AI = Initial amount (t=0)
F = Growth/decay factor
For half-life questions: F = ½
For doubling questions: F = 2
For losing an amount by n percent: F = 1 - (n)/100
For gaining an amount by n percent: F = 1 + (n/100)
For compounded interest of n percent: F = 1 + [n/(t/p)]
If only given 2 values, divide the second by the first to find F
t = elapsed time
p = length of one unit
Any equation that follows y = logbx where b > 0 and b ≠ 1
First list the ordered pairs for the parent exponential function
Then switch the domain and range to get the inverse
Graph following graphing standards
Name | Logarithmic Growth | Logarithmic Decay |
Formula | y = logbx , where b>1 | y = logbx , where 0<b<1 |
Domain | {x∈R|x>0} | {x∈R|x>0} |
Range | {y∈R} | {y∈R} |
X-intercepts | None | x = 1 |
Y-intercepts | y = 1 | None |
Max/Min | None | None |
Named points | None | None |
Asymptotes | x = 0 | x = 0 |
One-to-One? | Yes | Yes |
Odd/even/neither | Neither | Neither |
Intervals of increase or decrease | Always increasing | Always decreasing |
R.A.P’s | Plot the asymptote, with at lease one positive and one negative y integer, and continue without touching the asymptote | Plot the asymptote, with at lease one positive and one negative y integer, and continue without touching the asymptote |
Mapping formula | f(x) = abk(x-h) + v | f(x) = abk(x-h) + v |
Mapped coordinates | (af(x) + v, (1/k)x + h) | (af(x) + v, (1/k)x + h) |
A triangle has 3 side lengths and 3 angles
To solve, at least one side length and two other measurements must be known
Sine sin x = opp/hyp | Cosine cos x = adj/hyp | Tangent tan x = opp/adj |
Cosecant csc x = hyp/opp | Secant sec x = hyp/adj | Cotangent cot x = adj/opp |
Angle Sum of a Triangle a1 + a2 + a3 = 180∘ | Pythagorean Theorem a² + b² = c² | Sine Law sin A/a = sin B/b = sin C/c |
Cosine Law c² = a² + b² - 2ab(cos C) |
To solve, write down the applicable formula, and substitute appropriate variables
The tool must work with the proper triangle
Ratios and Pythagorean Theorem can only be used on right triangles
If there are multiple triangles, identify which one you are working in
Angle of depression - angle that goes down from a parallel line
Angle of elevation - angle that goes up from a parallel line
Cardinal directions are North, East, South, West
Bearing is the angle in one direction that moves towards one of the adjacent directions
True bearing - clockwise direction from true north
To solve problems
Draw and label neat diagrams with vertices and known measurements
Identify the RTF
Choose the proper tools and establish which triangle is being worked on
Use precise values
Consider the ambiguous case
degrees and radians measure angles
One complete rotation is 360∘ or 2π
A positive angle measure is a counter-clockwise rotation
Conversions
1∘ = π/180
1 = (180/π)∘
Multiply the fraction by the number of degrees or radians that are given
To find coterminal angles, add one rotation in units
To find the reference angle, use the quadrantal angles to determine the angle within a quadrant, and then isolate for the reference angle
The trigonometric ratios are as followed, where (x, y) is any point on θ’s terminal arm, and r is the (positive) distance from the point to the origin
sin θ = y/r | cos θ = x/r | tan θ = y/x |
csc θ = r/y | sec θ = r/x | cot θ = x/y |
Distance equation:
r = √(x² + y²)
To solve for ratios, take the given values, solve for the unknown value, and put the result into the ratio definitions
Related angles - angles that are in standard position with terminal arms that have the same reference angles
Principle angles - the first non-negative angle in standard position
Quadrantal Angles - angles in standard position that stop on an axis
Directed arc - an arc with an arrow indicating direction and amount of rotation
Let θ represent the reference angle
Quadrant | Coordinates | Sine | Cosine | Tangent | Formula |
1 | (x, y) | Positive | Positive | Positive | θ |
2 | (-x, y) | Positive | Negative | Negative | 180∘ - θ |
3 | (-x, -y) | Negative | Negative | Positive | 180∘ + θ |
4 | (x, -y) | Negative | Positive | Negative | 360∘ - θ |
Sine ratios are always between 1 and -1
Related angles with the same sine ratio will stop in the first and second quadrant
Solving triangles means to find all missing measures
The ambiguous case:
Given two side lengths and the angle opposite one of the sides
The given and is acute
The side opposite the given angle is shorter than the other given side
To solve:
Use the sine law to find the reference angle, and then the related angle that falls in quadrant 2
Draw a diagram of the two possible triangles
To find other angle measures, use the sum of angles of a triangle theorem
To find other sides, use sin law
There will be two possible answers, as there is an obtuse and acute angle
Name | Sine | Cosine | Tangent |
Formula | y = sin x | y = cos x | y = tan x |
Domain | {x∈R} | {x∈R} | {x∈R|x≠90∘±n180∘, n∈W} |
Range | {y∈R|-1≤y≤1} | {y∈R|-1≤y≤1} | {y∈R} |
Max/Min | Min. of 1, max. of 1 | Min. of 1, max of 1 | None |
Named points | None | None | None |
Asymptotes | None | None | Vertical: x = 90∘±n180∘, n∈W |
One-to-One? | No | No | No |
Odd/even/neither | Odd | Even | Odd |
Periodic? | Yes | Yes | Yes |
Period | 2π or 360∘ | 2π or 360∘ | π or 180∘ |
Amplitude | 1 | 1 | None |
R.A.P’s | All possible MMM’s and IBs. Only transform (-π/2, -1), (-π/6, -1/2), (0, 0), (π/6, 1/2), (π/2, 1) | All possible MMM’s and IBs. Only transform (0, 1), (π/3, 1/2), (π/2, 0), (2π/3, -1/2), (π, -1) | All values where y is -1, 0, or 1. Only transform (-45∘, -1), (0∘, 0), and (45∘, 1) |
Mapping formula | y = a sin[k(x-h)] + v | y = a cos[k(x-h)] + v | y = a tan[k(x-h)] + v |
For sine and cosine, always plot the MMM’s and IBs
There will be an MMM every quarter of a period
An IB will be 2/3 away from the max or min, and 1/3 away from a mid
For tangent, plot asymptotes
The unknown variable that must be solved is the argument
For simple arguments:
First solve for the ratio - isolate the function on one side
Based on the ratio, identify which quadrant the terminal arm(s) are in, and if it is a positive, negative, undefined, or 0 value
Draw a diagram
Identify the reference angle, using special triangles or arc-functions
Determine the principal angles
Find coterminal angles to fulfill the restrictions
For complex arguments:
Solve for the ratio
Replace the entire argument with just one variable
Based on the ratio, identify which quadrant the terminal arm(s) are in, and if it is a positive, negative, undefined, or 0 value
Draw a diagram
Identify the reference angle, using special triangles or arc-functions
Determine the principle angles
Input the principle angles into the entire original argument and solve
Multiply the parent period by the horizontal stretch/shrink factor
Add and subtract this number to the transformed principle angles to find all applicable angles
Amplitude = |a| | Max = |a| + v | Min = -|a| + v | Mid = v |
Period = 360∘/|k| | Period = 2π/|k| | Sine Phase Shift: xt = 1/k(90∘) + h | Cosine Phase Shift: xt = h |
To find equations:
Using the values above, find the variables
Before finding the phase shift variables, determine whether reflections will apply, and thus, if |a| and |k| will be positive or negative values
Find the phase shifts
Use the variable values to create a transformed parent equation
To transform asymptotes:
Find the location of one asymptote using: x = (1/k)(90∘) + h
Find the period using: period = 180∘/|k|
The domain cannot be the location of that one asymptote, ± the period
Commutative Property of Addition CPA a + b = b + a | Commutative Property of Multiplication CPM ab = ba |
Associative Property of Addition APA a + (b + c) = (a + b) + c | Associative Property of Multiplication APM a(bc) = (ab)c |
Identity Property of Addition IPOA a + 0 = a | Identity Property of Multiplication IPOM a(1) = a |
Distributive Property a(b + c) = ab + ac | Zero Property of Multiplication a(0) = 0 |
Separate the equation into its left and right side
Make substitutions and simplify, showing all steps and justifying
Try factoring and manipulating algebraically when stuck
Once the two sides are equal, state:
“LS = RS. Therefore, this is an identity!!!”
Reciprocal Identity csc x = 1/sin x | Reciprocal Identity sec x = 1/cos x | Reciprocal Identity cot x = 1/tan x |
Quotient Identity tan x = sin x/cos x | Quotient Identity cot x = cos x/sin x | Pythagorean Identity sin²x + cos²x = 1 |
Angles can be written as a sum of other angle measures
Using addition identities, 15∘ (60-45 or 45-30) and 75∘ (45 + 30) become special angles
Solve for the ratio, and apply negatives or positives as the quadrant requires
A sequence is a set of values in a specific order, usually connected by some sort of pattern or rule
A term is a single value, and the term number indicates the position of a term in a sequence
tn is used to refer to the nth term of a sequence
The general term is the formula that can be used to calculate the value of any term in the sequence, where n is the independent variable
An explicit formula for the general term is one that can be used to calculate the values of terms in a sequence based only on n
Arithmetic Sequence - A sequence where the difference between consecutive terms (the common difference) is constant
a is the value of the first term
d is the common difference (tn - tn-1)
Term # | 1 | 2 | 3 | 4 | … |
Term Value | a | a + 1d | a + 2d | a + 3d | … |
tn = a + (n - 1)d, n∈N
Geometric Sequence - A sequence where the ratio of consecutive terms (the common ratio) is constant
a is the value of the first term
r is the common ratio (tn/tn-1)
Term # | 1 | 2 | 3 | 4 | … |
Term Value | a | ar1 | ar² | ar³ | … |
tn = arn-1, n∈N
To solve, first prove that it is arithmetic/geometric using the common difference/ratio. Then, use the equation
A series is the sum of terms in a sequence
Sn means the sum of the first n terms
The arithmetic series of n terms is: Sn = n/2 [a + tn], or Sn = n/2 [2a + (n-1)d]
The geometric series of n terms is: Sn = a(rn - 1)/ (r - 1)
Use the variables given and input them
Sometimes, n will have to be solved through a sequence first
Simple interest is arithmetic, and compounded interest is geometric
Simple interest
A = P + Prt
I = Prt
I is the amount of interest, P is the principal, r is the annual interest rate, t is the time elapsed in years, and A is the accrued amount
Compound interest
A = P(1 + i)n
PV = (FV)/(1 + i)n
I = A - P
Variables:
I - amount of interest
P/PV - principal
r - annual interest rate
t - time elapsed in years
A/FV - accrued amount
i - interest rate per period (annual rate/periods per year)
n - time elapsed in number of periods
An annuity is a sum of payments
Accrued annuity - payments are made over time to collect a larger fund
Present value annuity - When a sum of money is put in and payments come out over time
Simple ordinary annuity - the interval between payments is the same as compounding periods, and payments are made at the end of each period
Timelines
Make payments at the end of each period
The last payment should not have any factors besides the initial payment
The first payment should be n-1
Simple, Ordinary Annuity Formulas
A = R[(1 + i)n -1]/i
A - accrued amount
R - regular payment
i - interest rate per compounding period
n - number of compounding periods