PreCalc Unit 1
Numbers
Rational Numbers
½ , -3/7, 46, 0.77 - shown as fractions
Integers
… -3, -2, -1, 0
Natural Numbers
1, 2, 3
Irrational Numbers
root3, root5, pi - non repeating fractions
Properties
Communitive Prop of Addition
When we add two numbers, order doesn’t matter.
inverted
Communitive Prop of Multiplication
When we multiply two numbers, order doesn’t matter.
inverted
Associative Prop of Addition
When we add three numbers, it doesn’t matter which two we add first
same order diff ()
Associative Prop of Multiplication
When we multiply three numbers, it doesn’t matter which two we multiply first.
same order diff ()
Distributive Prop
When we multiply a number by the sum of two numbers, we get the same result as we get if we multiply the number by each of the terms and then add the results.
Notations
set builder notation
A = { x | … }
interval notation
( denotes and open
[ denotes a closed
such as but not limited to, (0,0), [0,0], (0,0]
Inequalities
the real number lines
numbers that are less are on the left
numbers that are more on the right
a < b when a is less than b
b > a when b is greater than a
Sets
U - union
all numbers in a given set
upside down U - intersection
numbers that are the same - “intersect” - in a set
be careful when writing them out - make sure graph is correct
Intervals in terms of Inequalities
( open also OPEN circle
< or >
[ closed also CLOSED circle
<= or =>
Absolute Value
|a| and a is positive = +
|-a| and a negative = -(-a) = +
used to show distance
Hardest: 77, 86, 87
Radicals and Exponents
Exponents
power of 0 = 1
power of 1 = base number
multiplying exs = adding
dividing exs = subtracting
() = multiplying
negative = move to the denominator or vice versa
Radicals
¼ = 4root
2/3 = 3rootx²
radical x radical breaks free
get radical out of denominator by multiplying by root top and bottom
Scientific notation
move decimal —→ negative
move decimal ←— positive
hardest: 68, 75,
Factoring
refer to notes if needing special equations
pretty simple/self explanatory
good at this <3
GO OVER SPECIAL RULES
hardest: 33,44, 79, 136
identifying domain
anything in the numerator is = all real numbers
anything in the numerator + root = >=0
anything in the denominator /= 0
anhting in the denominator + root >0
simplifying rational expressions
numerator/denominator (could be multiplied by another)
factor and cancel common terms
if dividing two —> flip the second and multiply + factor + cancel
adding and subtracting two fractions
find LCD
multiply numerators by the denominator factors they don’t already have
simplify
factor and cancel
simplify all the way
compound fractions
same steps as before just x2
take the bottom fraction flip and multiply by the first
factor and cancel
simplify all the way
rationalize the denominator
if just root —> multiply by root to break free on top and bottom
if cube root and x² —> multiply by cube root x (x² x x break free) on top and bottom
if two terms (one real and one root) multiply by the pos (if neg) or by the neg (if pos)
same for numerator
hardest: 90,79
linear equations
plug in x when given and solve
fractions with linear equations
multiply numerators with both denominators to cancel out
simplify —> factor —> cancle
simplify further
solving for variables
get the variable alone
solving using factoring
factor then set x to 0 and solve
completing the square
move the real number to the zero side
add (b/2)² to both sides
simplify the perfect square and solve
make sure root is PLUS AND MINUS
quadratic equations
-b +- root b² - 4ac/ 2a
using the discriminate to determine how many answers
b² - 4ac
- = none
+ = two
0 = one
absolute value
set the = to neg and pos
solve —> two x’s
CHECK SOLUTIONS
hardest: 118, 133
sum and difference of imaginary numbers
in the form a+bi
mulitply the two with the FOIL method
simplify i
single fraction with in in the denominator
do what you would do when rationalizing the denominator
simplify i
similar to complex fractions
simplify i
cannot multiply two negative roots
can use the quadratic equation
conjugates
change the sign connecting the two terms
hardest: 51, 55,
word problems.
d = rt
hardest: 70 and 64 hw and last two on notes
Linear inequalities
get x alone
graphing:
< or > means open circle
<= or => means closed circle
set notation
< or > means ()
infinity is always ()
<= or >= means []
nonlinear inequalities
kind of like factoring where you get two x’s
make everything on one side and 0 on the other
< or <= determines the sign of the inequality answer
open circle/closed circle and ()/[]
check each portion of your graph by inputting a number either higher/lower/in between to determine where to draw ur line
the set notation depends on the last step
if lines go ←— and —→ without connecting in between you will have two set notations with U in between
DO THE SAME IF YOU HAVE 3 X’s
check all
if one point doesn’t have a line do {number} with U in between
nonlinear inequalities with fractions
when everything is on the correct side
set x = 0
once you get your factors you have to make sure they are included in the inequality answer (so open or closed circle)
if it is in the denominator (the factor) it has to be an open circle
RULE ONLY APPLIES IF OG INEQUALITY USES <= or =>
if of uses < or > there is no need to check
same rules as before
when inequality is not set to 0
move it to other side and multiply numerator and denominator by og denominator so you have one fraction
then follow same steps as before
if there is an x² that is an additional root
absolute value inequality
works the same as a regular
you’ll get your immediate answer after solving
graphing is easy
hardest: 87,101,
graphing domain and range
y is horizontal
x is vertical
included in graph = filled in line
not included in graph = dashed line
distance
d = root (x2-x1)² + (y2-y1)²
midpoint
(x2+x1/2, y2+y1/2)
Areas
rectangle/square = lw
trapezoid = (b1+b2/2)h
isoceles
two sides of the triangle are the same
given midpoint and not the second point
set midpoint x = (x2+x1/2)
input what you have and solve for x2
same for y
y and x-intercepts
set x = 0 for y-intercept and solve
set y = 0 for x-intercept and solve
testing symmetry
x-axis
set y to -y
y-axis
set x to -x
origin
set x to -x and y to -y
if they equal the of equation it has that symmetry u tested for
when using square root for x and y intercepts
if both sides need to be squared / rooted ex: x² = 9 is when there will be BOTH negative and positive answer
if only one side needs to be rooted ex: x = root9 there will only be ONE positive answer
equation of the circle
(x - h)² + (y - k)² = r²
the center is (h, k) —> positive if inside is neg
graphing circle
find center and radius
graph the center, the circle will not extend past the radius on all sides
hardest: 100,
slope
y2-y1/x2-x1
point slope form
y-y1 = m(x-x1)
(x1, y1) point on the graph
m is slope
slope intercept form
y = mx +b
m is slope
b os y-intercept
finding an equation perpendicualr to the line
find given slope —> find the opposite
if positive —> negative
if a fraction/number —> flip it
must do both of those
put given points and new slope into point slope form
simplify to slope intercept form
finding an equation parallel to the line
find given slope —> slope stays the same for new equation
put given points and same slope into point slope form
simplify to slope intercept form
if given an equation like x = 5
slope = undefined
y-intercept: none
graph is a verticle line
directly proportional
y=kx
y is directly proportional to x
inversely proportional
y=k/x
y is inversely proportional to x
input any given values
answer should be the variable and k as a number
if it says the two variables = the same just make them the same variable to solve
the actual equation will have the actual variable
when asked how y is changed when multiplying the other variables
ignore the other variables and put in the new values
multiply and simplify
take the real numbers out of the equation
answer
hardest: 35
PRACTICE TEST HARDEST: 7, 11, bonus
Numbers
Rational Numbers
½ , -3/7, 46, 0.77 - shown as fractions
Integers
… -3, -2, -1, 0
Natural Numbers
1, 2, 3
Irrational Numbers
root3, root5, pi - non repeating fractions
Properties
Communitive Prop of Addition
When we add two numbers, order doesn’t matter.
inverted
Communitive Prop of Multiplication
When we multiply two numbers, order doesn’t matter.
inverted
Associative Prop of Addition
When we add three numbers, it doesn’t matter which two we add first
same order diff ()
Associative Prop of Multiplication
When we multiply three numbers, it doesn’t matter which two we multiply first.
same order diff ()
Distributive Prop
When we multiply a number by the sum of two numbers, we get the same result as we get if we multiply the number by each of the terms and then add the results.
Notations
set builder notation
A = { x | … }
interval notation
( denotes and open
[ denotes a closed
such as but not limited to, (0,0), [0,0], (0,0]
Inequalities
the real number lines
numbers that are less are on the left
numbers that are more on the right
a < b when a is less than b
b > a when b is greater than a
Sets
U - union
all numbers in a given set
upside down U - intersection
numbers that are the same - “intersect” - in a set
be careful when writing them out - make sure graph is correct
Intervals in terms of Inequalities
( open also OPEN circle
< or >
[ closed also CLOSED circle
<= or =>
Absolute Value
|a| and a is positive = +
|-a| and a negative = -(-a) = +
used to show distance
Hardest: 77, 86, 87
Radicals and Exponents
Exponents
power of 0 = 1
power of 1 = base number
multiplying exs = adding
dividing exs = subtracting
() = multiplying
negative = move to the denominator or vice versa
Radicals
¼ = 4root
2/3 = 3rootx²
radical x radical breaks free
get radical out of denominator by multiplying by root top and bottom
Scientific notation
move decimal —→ negative
move decimal ←— positive
hardest: 68, 75,
Factoring
refer to notes if needing special equations
pretty simple/self explanatory
good at this <3
GO OVER SPECIAL RULES
hardest: 33,44, 79, 136
identifying domain
anything in the numerator is = all real numbers
anything in the numerator + root = >=0
anything in the denominator /= 0
anhting in the denominator + root >0
simplifying rational expressions
numerator/denominator (could be multiplied by another)
factor and cancel common terms
if dividing two —> flip the second and multiply + factor + cancel
adding and subtracting two fractions
find LCD
multiply numerators by the denominator factors they don’t already have
simplify
factor and cancel
simplify all the way
compound fractions
same steps as before just x2
take the bottom fraction flip and multiply by the first
factor and cancel
simplify all the way
rationalize the denominator
if just root —> multiply by root to break free on top and bottom
if cube root and x² —> multiply by cube root x (x² x x break free) on top and bottom
if two terms (one real and one root) multiply by the pos (if neg) or by the neg (if pos)
same for numerator
hardest: 90,79
linear equations
plug in x when given and solve
fractions with linear equations
multiply numerators with both denominators to cancel out
simplify —> factor —> cancle
simplify further
solving for variables
get the variable alone
solving using factoring
factor then set x to 0 and solve
completing the square
move the real number to the zero side
add (b/2)² to both sides
simplify the perfect square and solve
make sure root is PLUS AND MINUS
quadratic equations
-b +- root b² - 4ac/ 2a
using the discriminate to determine how many answers
b² - 4ac
- = none
+ = two
0 = one
absolute value
set the = to neg and pos
solve —> two x’s
CHECK SOLUTIONS
hardest: 118, 133
sum and difference of imaginary numbers
in the form a+bi
mulitply the two with the FOIL method
simplify i
single fraction with in in the denominator
do what you would do when rationalizing the denominator
simplify i
similar to complex fractions
simplify i
cannot multiply two negative roots
can use the quadratic equation
conjugates
change the sign connecting the two terms
hardest: 51, 55,
word problems.
d = rt
hardest: 70 and 64 hw and last two on notes
Linear inequalities
get x alone
graphing:
< or > means open circle
<= or => means closed circle
set notation
< or > means ()
infinity is always ()
<= or >= means []
nonlinear inequalities
kind of like factoring where you get two x’s
make everything on one side and 0 on the other
< or <= determines the sign of the inequality answer
open circle/closed circle and ()/[]
check each portion of your graph by inputting a number either higher/lower/in between to determine where to draw ur line
the set notation depends on the last step
if lines go ←— and —→ without connecting in between you will have two set notations with U in between
DO THE SAME IF YOU HAVE 3 X’s
check all
if one point doesn’t have a line do {number} with U in between
nonlinear inequalities with fractions
when everything is on the correct side
set x = 0
once you get your factors you have to make sure they are included in the inequality answer (so open or closed circle)
if it is in the denominator (the factor) it has to be an open circle
RULE ONLY APPLIES IF OG INEQUALITY USES <= or =>
if of uses < or > there is no need to check
same rules as before
when inequality is not set to 0
move it to other side and multiply numerator and denominator by og denominator so you have one fraction
then follow same steps as before
if there is an x² that is an additional root
absolute value inequality
works the same as a regular
you’ll get your immediate answer after solving
graphing is easy
hardest: 87,101,
graphing domain and range
y is horizontal
x is vertical
included in graph = filled in line
not included in graph = dashed line
distance
d = root (x2-x1)² + (y2-y1)²
midpoint
(x2+x1/2, y2+y1/2)
Areas
rectangle/square = lw
trapezoid = (b1+b2/2)h
isoceles
two sides of the triangle are the same
given midpoint and not the second point
set midpoint x = (x2+x1/2)
input what you have and solve for x2
same for y
y and x-intercepts
set x = 0 for y-intercept and solve
set y = 0 for x-intercept and solve
testing symmetry
x-axis
set y to -y
y-axis
set x to -x
origin
set x to -x and y to -y
if they equal the of equation it has that symmetry u tested for
when using square root for x and y intercepts
if both sides need to be squared / rooted ex: x² = 9 is when there will be BOTH negative and positive answer
if only one side needs to be rooted ex: x = root9 there will only be ONE positive answer
equation of the circle
(x - h)² + (y - k)² = r²
the center is (h, k) —> positive if inside is neg
graphing circle
find center and radius
graph the center, the circle will not extend past the radius on all sides
hardest: 100,
slope
y2-y1/x2-x1
point slope form
y-y1 = m(x-x1)
(x1, y1) point on the graph
m is slope
slope intercept form
y = mx +b
m is slope
b os y-intercept
finding an equation perpendicualr to the line
find given slope —> find the opposite
if positive —> negative
if a fraction/number —> flip it
must do both of those
put given points and new slope into point slope form
simplify to slope intercept form
finding an equation parallel to the line
find given slope —> slope stays the same for new equation
put given points and same slope into point slope form
simplify to slope intercept form
if given an equation like x = 5
slope = undefined
y-intercept: none
graph is a verticle line
directly proportional
y=kx
y is directly proportional to x
inversely proportional
y=k/x
y is inversely proportional to x
input any given values
answer should be the variable and k as a number
if it says the two variables = the same just make them the same variable to solve
the actual equation will have the actual variable
when asked how y is changed when multiplying the other variables
ignore the other variables and put in the new values
multiply and simplify
take the real numbers out of the equation
answer
hardest: 35
PRACTICE TEST HARDEST: 7, 11, bonus