AP Precalculus Terms & Formulas
NOTE: I accidentally deleted the original; This is supposed to be an “ultimate guide” but I don’t think we can finish it before the AP exam; However, all formulas for all units are posted!! I’ll leave the notes for Unit 1 here in case you want to read them, and will add more notes when they are ready!
Credit to: Shreya Shah, Brooke Vang :)
Important Overall Exam Notes and Tips:
Repeat what is said in the question
Read very carefully, and answer only what is asked (especially with limits- it might only ask for one)
__________________________________________________________________________________________________________UNIT 1:
Terms:
Function: a mathematical relation that maps a set of input values to a set of output values such that each input value is called the domain of the function, and the set of output values is called the range of the function
Inflection Point: where a curve changes from concave up to concave down or concave down to concave up
x-intercepts: the x-intercepts of the graph of f, if any, are the solutions of the equation f(x)=0 or (x,0)
y-intercepts: if x=0 is in the domain of a function y=f(x), then the y-intercept of the graph of f is the value of f and 0, f(0), or (0,y)
Average Rate of Change (AROC): the average rate of change between any two points on a graph of f(x) is the slope through these points
Instantaneous Rate of Change: using the average rate of change over small intervals; the rate that the y-values would change if the x-values changed at that point.
Polynomial Function: a monomial or a sum of monomials
Turning Point: a point where the graph of a function changes direction from upwards to downwards, or from downwards to upwards
End Behavior: the direction of the graph of a function as you move to the left and to the right, away from the origin
Relative/Local Extrema: y-values on the graph of a function where the function changes from increasing to decreasing or decreasing to increasing
Absolute/Global Extrema: the highest or lowest y-values on the graph of a function or on a specified domain of a function
Odd Function: must travel through the origin and f(-x)=-f(x)
Even Function: reflection over y-axis and f(-x)=f(x)
Imaginary Number: when the value of the radicand is negative, the root is an imaginary number; i=-1
Complex Number: a number of the form a+bi where a is the real part of the complex number and bi is the imaginary part of the complex number
Complex Conjugate: if (a+bi) is a factor then (a-bi) is also a factor
Formulas:
Average Rate of Change: AROC=y2-y1x2-x1
Find the y-values of the function for the given interval
Find the slope between those two points
Binomial Expansion: (ab)n
Use Pascal’s Triangle (n+1 terms)
Transformations to a Quadratic: f(x)=a(b(x-h)2+k
a: possible vertical reflection and/or dilation by a factor of a
b: possible horizontal reflection and/or dilation by a factor of 1b (must be factored out)
h: possible horizontal translation in the direction -h
k: possible vertical translation in the direction k
Important Notes:
Rule of Four (G.N.A.W.): four ways to represent a function
Graphically: by points on a coordinate plane where input values are on the horizontal axis and output values are on the vertical axis
Numerically: by a table or a set of ordered pairs that match input values with output values
Algebraically: by an equation in two variables
Words: by verbally describing how the input variable is related to the output variable
Attributes of Polynomials:
If the graph of f has a positive rate of change, then the graph of f is increasing
If the graph of f has a negative rate of change, then the graph of f is decreasing
If the rate of change of f is increasing (slope increases), then the graph of f is concave up
The average rate of change over equal-length input-value intervals is increasing, so the graph is concave up
If the rate of change of f is decreasing (slope decreases), then the graph of f is concave down
The average rate of change over equal-length input-value intervals is decreasing, so the graph is concave down
For any linear function, the average rate of change over any length input-value interval is constant
The average rate of change is changing at a rate of zero
For any quadratic function, the average rate of change over consecutive equal-length input-value intervals can be given by a linear function
The average rate of change is changing at a constant rate
1.1 🠆 Change in Tandem
If a function f is defined by an equation and no domain is specified, then the domain will be the largest set of real numbers for which the value of f(x) is a real number. Exclude any real numbers from a function’s domain that cause division by zero (undefined) or that result in an even root of a negative number (imaginary number).
A function increases over an open interval of its domain if its graph rises from left to right on the interval. A function decreases over an open interval of its domain if its graph falls from left to right on the interval. A function is constant over an open interval of its domain if its graph is horizontal on the interval.
1.2 🠆 Rates of Change
The average rate of change is the slope between any two points on the graph of f(x)
Instantaneous rate of change is finding the rate of change of a function at a given point
You can estimate the rate of change at a point by finding the average rate of change over a very small interval
You can estimate rates of change at two different points by estimating individual rates of change using a tangent line
The slope of the line tangent to the graph of f at any given point is the true rate of change of f at that point
1.3 🠆 Average Rate of Change in Linear and Quadratic Functions
For any linear function, the average rate of change over any length input-value interval is constant
The average rate of change is changing at a rate of zero
For any quadratic function, the average rate of change over consecutive equal-length input-value intervals can be given by a linear function
The average rate of change is changing at a constant rate
1.4 🠆 Polynomial Functions and Rate of Change
Degree: the highest exponent (only on polynomials in standard form)Polynomial functions of an even degree will have either a global (absolute) maximum or a global (absolute) minimum
A function is concave up on an open interval if the graph looks like a “U” or part of a smile
A function is concave down on an open interval if the graph looks like an upside down “U” or part of a frown
A function f has a point of inflection at c on an open interval if a graph changes concavity
It can occur at 3 different places:
At a zero with a multiplicity of 3
Estimate a possible point of inflection between two consecutive extreme values (at the midpoint between the relative maximum/relative minimum values)
Estimate a possible point of inflection between a zero, multiplicity of 3, and the closest relative extreme value
__________________________________________________________________________________________________________UNIT 2:
Formulas:
Arithmetic (Linear) Sequences: an=a0+dn or an+d(n-k)
The common difference is added forward and subtracted backward
Geometric (Exponential) Sequences: gn=g0(r)n or gn=gk(r)n-k
The common ratio is multiplied forward and divided backward
Exponential Functions: y=a(b)x
a and b are non-zero constants and b1
Always has one horizontal asymptote y=k
The domain is all real numbers
All increasing or all decreasing
All concave up or all concave down
For consistent input values, output values change proportionally
Growth for r>1
Decay for 0<r<1
End behavior: xg(x)= or xg(x)=0
Exponential Properties: bm+n=bmbn, bmn=(bm)n, b-n=1bn, b1k=kb
Logarithmic Functions: y=alogbx
a and b are non-zero constants, b>0, b1
Always has one vertical asymptote x=h
The range is all real numbers
All increasing or all decreasing
All concave up or all concave down
Input values change proportionately for consistent output values
End behavior: x0+f(x)= or xf(x)=
Lim (function)
x to infinity, -infinity, ha, va, 0 (depends on the function!)
__________________________________________________________________________________________________________UNIT 3:
Formulas:
f(x+k)=f(x)
The period of the function is the smallest possible k
k is the translation amount or the period
sin=yr
cos = xr
tan = yx or tan = sin cos
csc=1sin
sec=1cos
cot=cossin
radians = arc lengthradius
Arc length: r(theta)
Coordinate Point: (rcos,rsin)
Period: pd = 2b
Pythagorean Identity: sin2+cos2 = 1
Pythagorean Identity: 1+cot2=csc2
Pythagorean Identity: tan2+1=sec2
Sine Double Angle: sin(2) = 2sincos
Cosine Double Angle: cos(2) = cos2-sin2
Sine Sum: sin(+) = sincos+sincos
Sine Difference: sin(-) = sincos-sincos
Cosine Sum: cos(+) = coscos-sinsin
Cosine Difference: cos(-) = coscos+sinsin
Vertical Asymptotes: Only 4 Trig Functions
tan: pi/ 2+ kpi
csc: kpi
cot: kpi
sec: pi/2+kpi and 3pi/2+kpi
Polar Formulas:
Rectangular-Polar: r = sqrt(x² + y²) & tanx= y/x (ADD PI IF x<0!!)
Polar-Rectangular: (rcosx, rsinx)
Increasing: above the x-axis
Decreasing: below the x-axis
NOTE: I accidentally deleted the original; This is supposed to be an “ultimate guide” but I don’t think we can finish it before the AP exam; However, all formulas for all units are posted!! I’ll leave the notes for Unit 1 here in case you want to read them, and will add more notes when they are ready!
Credit to: Shreya Shah, Brooke Vang :)
Important Overall Exam Notes and Tips:
Repeat what is said in the question
Read very carefully, and answer only what is asked (especially with limits- it might only ask for one)
__________________________________________________________________________________________________________UNIT 1:
Terms:
Function: a mathematical relation that maps a set of input values to a set of output values such that each input value is called the domain of the function, and the set of output values is called the range of the function
Inflection Point: where a curve changes from concave up to concave down or concave down to concave up
x-intercepts: the x-intercepts of the graph of f, if any, are the solutions of the equation f(x)=0 or (x,0)
y-intercepts: if x=0 is in the domain of a function y=f(x), then the y-intercept of the graph of f is the value of f and 0, f(0), or (0,y)
Average Rate of Change (AROC): the average rate of change between any two points on a graph of f(x) is the slope through these points
Instantaneous Rate of Change: using the average rate of change over small intervals; the rate that the y-values would change if the x-values changed at that point.
Polynomial Function: a monomial or a sum of monomials
Turning Point: a point where the graph of a function changes direction from upwards to downwards, or from downwards to upwards
End Behavior: the direction of the graph of a function as you move to the left and to the right, away from the origin
Relative/Local Extrema: y-values on the graph of a function where the function changes from increasing to decreasing or decreasing to increasing
Absolute/Global Extrema: the highest or lowest y-values on the graph of a function or on a specified domain of a function
Odd Function: must travel through the origin and f(-x)=-f(x)
Even Function: reflection over y-axis and f(-x)=f(x)
Imaginary Number: when the value of the radicand is negative, the root is an imaginary number; i=-1
Complex Number: a number of the form a+bi where a is the real part of the complex number and bi is the imaginary part of the complex number
Complex Conjugate: if (a+bi) is a factor then (a-bi) is also a factor
Formulas:
Average Rate of Change: AROC=y2-y1x2-x1
Find the y-values of the function for the given interval
Find the slope between those two points
Binomial Expansion: (ab)n
Use Pascal’s Triangle (n+1 terms)
Transformations to a Quadratic: f(x)=a(b(x-h)2+k
a: possible vertical reflection and/or dilation by a factor of a
b: possible horizontal reflection and/or dilation by a factor of 1b (must be factored out)
h: possible horizontal translation in the direction -h
k: possible vertical translation in the direction k
Important Notes:
Rule of Four (G.N.A.W.): four ways to represent a function
Graphically: by points on a coordinate plane where input values are on the horizontal axis and output values are on the vertical axis
Numerically: by a table or a set of ordered pairs that match input values with output values
Algebraically: by an equation in two variables
Words: by verbally describing how the input variable is related to the output variable
Attributes of Polynomials:
If the graph of f has a positive rate of change, then the graph of f is increasing
If the graph of f has a negative rate of change, then the graph of f is decreasing
If the rate of change of f is increasing (slope increases), then the graph of f is concave up
The average rate of change over equal-length input-value intervals is increasing, so the graph is concave up
If the rate of change of f is decreasing (slope decreases), then the graph of f is concave down
The average rate of change over equal-length input-value intervals is decreasing, so the graph is concave down
For any linear function, the average rate of change over any length input-value interval is constant
The average rate of change is changing at a rate of zero
For any quadratic function, the average rate of change over consecutive equal-length input-value intervals can be given by a linear function
The average rate of change is changing at a constant rate
1.1 🠆 Change in Tandem
If a function f is defined by an equation and no domain is specified, then the domain will be the largest set of real numbers for which the value of f(x) is a real number. Exclude any real numbers from a function’s domain that cause division by zero (undefined) or that result in an even root of a negative number (imaginary number).
A function increases over an open interval of its domain if its graph rises from left to right on the interval. A function decreases over an open interval of its domain if its graph falls from left to right on the interval. A function is constant over an open interval of its domain if its graph is horizontal on the interval.
1.2 🠆 Rates of Change
The average rate of change is the slope between any two points on the graph of f(x)
Instantaneous rate of change is finding the rate of change of a function at a given point
You can estimate the rate of change at a point by finding the average rate of change over a very small interval
You can estimate rates of change at two different points by estimating individual rates of change using a tangent line
The slope of the line tangent to the graph of f at any given point is the true rate of change of f at that point
1.3 🠆 Average Rate of Change in Linear and Quadratic Functions
For any linear function, the average rate of change over any length input-value interval is constant
The average rate of change is changing at a rate of zero
For any quadratic function, the average rate of change over consecutive equal-length input-value intervals can be given by a linear function
The average rate of change is changing at a constant rate
1.4 🠆 Polynomial Functions and Rate of Change
Degree: the highest exponent (only on polynomials in standard form)Polynomial functions of an even degree will have either a global (absolute) maximum or a global (absolute) minimum
A function is concave up on an open interval if the graph looks like a “U” or part of a smile
A function is concave down on an open interval if the graph looks like an upside down “U” or part of a frown
A function f has a point of inflection at c on an open interval if a graph changes concavity
It can occur at 3 different places:
At a zero with a multiplicity of 3
Estimate a possible point of inflection between two consecutive extreme values (at the midpoint between the relative maximum/relative minimum values)
Estimate a possible point of inflection between a zero, multiplicity of 3, and the closest relative extreme value
__________________________________________________________________________________________________________UNIT 2:
Formulas:
Arithmetic (Linear) Sequences: an=a0+dn or an+d(n-k)
The common difference is added forward and subtracted backward
Geometric (Exponential) Sequences: gn=g0(r)n or gn=gk(r)n-k
The common ratio is multiplied forward and divided backward
Exponential Functions: y=a(b)x
a and b are non-zero constants and b1
Always has one horizontal asymptote y=k
The domain is all real numbers
All increasing or all decreasing
All concave up or all concave down
For consistent input values, output values change proportionally
Growth for r>1
Decay for 0<r<1
End behavior: xg(x)= or xg(x)=0
Exponential Properties: bm+n=bmbn, bmn=(bm)n, b-n=1bn, b1k=kb
Logarithmic Functions: y=alogbx
a and b are non-zero constants, b>0, b1
Always has one vertical asymptote x=h
The range is all real numbers
All increasing or all decreasing
All concave up or all concave down
Input values change proportionately for consistent output values
End behavior: x0+f(x)= or xf(x)=
Lim (function)
x to infinity, -infinity, ha, va, 0 (depends on the function!)
__________________________________________________________________________________________________________UNIT 3:
Formulas:
f(x+k)=f(x)
The period of the function is the smallest possible k
k is the translation amount or the period
sin=yr
cos = xr
tan = yx or tan = sin cos
csc=1sin
sec=1cos
cot=cossin
radians = arc lengthradius
Arc length: r(theta)
Coordinate Point: (rcos,rsin)
Period: pd = 2b
Pythagorean Identity: sin2+cos2 = 1
Pythagorean Identity: 1+cot2=csc2
Pythagorean Identity: tan2+1=sec2
Sine Double Angle: sin(2) = 2sincos
Cosine Double Angle: cos(2) = cos2-sin2
Sine Sum: sin(+) = sincos+sincos
Sine Difference: sin(-) = sincos-sincos
Cosine Sum: cos(+) = coscos-sinsin
Cosine Difference: cos(-) = coscos+sinsin
Vertical Asymptotes: Only 4 Trig Functions
tan: pi/ 2+ kpi
csc: kpi
cot: kpi
sec: pi/2+kpi and 3pi/2+kpi
Polar Formulas:
Rectangular-Polar: r = sqrt(x² + y²) & tanx= y/x (ADD PI IF x<0!!)
Polar-Rectangular: (rcosx, rsinx)
Increasing: above the x-axis
Decreasing: below the x-axis