sat index cards
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Numbers and Divisibility
Rational Numbers
Real numbers/fractions that can repeat or terminate.
Examples: 33, 1/3
Irrational Numbers
Real numbers/fractions that do not repeat or terminate.
Example: π
Integers
Positive or negative whole numbers. 0 is also considered an integer.
Example: 4, -2
Non-Integers
Positive or negative numbers that are in fraction form.
Ex: 25/7
Imaginary Numbers
Numbers that are not real, have an i in them.
Ex:
Divisible by 2
Even #’s
End in 0,2,4,6 or 8
Divisible by 5
Ends in a Zero or Five
Divisible by 10
Ends in Zero
Divisible by 3
Sum digits together
Sum must be divisible by 3
Divisible by 9
Add digits together
Sum of the digits must be divisible by 9
Divisible by 4
If the last two digits are divisible by 4 than the whole number is
Divisible by 6
If its divisible by 2 and 3
Consecutive
• One right after another, the next possible one.
Distinct
• =Different
Factors
• Any group of numbers or variables that when multiplied give the original number/variable
Multiple
• The result of multiplying a number by an integer.
• EX: Multiples of 4:
…,-8,-4,0,4,8,12…
• Union• Combining sets without
writing the repeats
• Intersection• The overlap of sets
Percent Increase or Decrease
100%current original
original
− ×
Exponent and Root Rules!
How to multiply two powers with same base?
a3 * a5 = a3 + 5 = a8
How to divide two powers with the same base?
a5 / a3 = a5-3 = a2
Multiplying exponents
(a2)3= a2*3= a6
Zero as an exponent
a0=1
ANYTHING TO THE ZERO POWER EQUALS 1
Exponent of 1
X1=X
Anything to the exponent of 1, is THAT number
Negative Exponents
a-1= 1/a
Simplifying Radicals with multiplication
Can be written as ba
Simplifying Radicals with division
baba /
Alternate form of square root
= a1/2a
Alternate form of cube root
= a 1/33 a
3 2a = a2/3 = ( )23 a
Graphing/ Writing Equations of Lines
Coordinate Plane
Origin
Y-axis
X-axis
Quadrant IQuadrant 2
Quadrant 3 Quadrant 4
Slope Formula
2 1
2 1
y y risem
x x run
−= =−
Distance Formula
2 22 1 2 1( ) ( )d y y x x= − + −
Midpoint Formula
1 2 1 2,2 2
x x y y+ + = ÷
Vertical Lines
•Think vertebra to help with visual•Undefined Slope! (cannot walk up walls)•Form x=#
Horizontal Lines
•Think horizon to help with visual•Slope = Zero (walking across left to right there is no incline or decline)•Form y=#
Slope-Intercept Form
y mx b= +
Parallel Lines
•Do not intersect•Have the same slopes•Symbol: ||
Perpendicular Lines
•Intersect at a right angle/90⁰•Have slopes that are opposite, reciprocals of each other (flip it and switch it)•Symbol: ⊥
X-intercepts
•Also known as roots and zeros•Where the graph crosses the x-axis•Plug 0 in for y and solve for x•Answer: (#,0) as an ordered pair
y-intercepts
•Where the graph crosses the y-axis•Plug 0 in for x and solve for y•Answer: (0,#) as an ordered pair
Directly Proportional
As x increases, y increasesOR
As x decreases, y decreases
y kx=
Inversely Proportional
As x increases, y decreasesOR
As x decreases, y increases
ky
x=
Function Notationand Variables
Function
• Equation where every input has exactly one output– For each x-value there is one y-value
• F(x)=y– F(x)=mx + b
• Plug in x to find F(x) or y
F(x)=2x+4F(-3)
F(-3)=2(-3)+4
F(-3)=(-6)+4
F(-3)=-2
F(x)=4x+5F(x)=25
25=4x+5
25-5=4x
20=4x
4
X=5
F(x) + G(x)F of x added to G of x
• Add the two functions together
F(x) – G(x)F of x subtracted from G of
x
• Subtract the two functions
F(G(x))F of G of x
• Plug the function of G(x) into the x-variables in the function F(x)
F(x) G(x)●F of x multiplied by G of x
• Multiply the two functions together
F(x) / G(x)F of x divided by G of x
• Divide the two notations
Graph Shiftsf(x)
f(x) + 3
• The f(x) graph moves up 3 places
f(x) - 5
• The f(x) graph moves down 5 places
f(x)
-f(x)
• The f(x) graph is reflected over x-axis
f(-x)
• The graph of f(x) is reflected over the y-axis
f(x + 2)
• The f(x) graph moves LEFT 2
f(x – 4)
• The f(x) graph moves RIGHT 4
Geometry
Sum of Interior Angles of a Triangle?
A
B
C
0180m A m B m C∠ + ∠ + ∠ =
Perimeter of Triangle
a + b + c = perimeter
a b
c
Exterior Angle Theorem
A
B
C D
m A m B m D∠ + ∠ = ∠
Pythagorean Theorem
a
b
C=hypotenuse
2 2 2a b c+ =
Area of a Triangle
Area Formula: ½ x base x height
30⁰-60⁰-90⁰ Right Triangles
60⁰
30⁰
3n
n2n
45⁰-45⁰-90⁰ Right Triangles
n2n
n
45⁰
45⁰
Congruent Triangles
Scalene Triangle
Triangle with no equal sides.
Isosceles Triangle
Triangle with two equal sides. The corresponding angles
are congruent as well.
Equilateral & Equiangular Triangle
(If equilateral equiangular and vice
versa)
Triangle that has three equal sides and three equal angles
that are 60⁰.
Right Triangle
Leg
Hypotenuse
Leg
Obtuse Triangle
Triangle that has one obtuse angle.
Acute Triangle
Triangle that has three acute angles.
Quadrilateral
Four sided Figure
Area of a Quadrilateral
A=base X height
Parallelogram
• Quadrilateral with the following properties:1. Opposite sides are parallel2. Opposite sides are congruent3. Diagonals bisect each other4. Opposite angles are congruent
Rectangle
• Parallelogram that has all of those properties plus the following:1. All angles are 90⁰2. Diagonals are congruent
Rhombus
• Parallelogram that has all of those properties plus the following:1. All sides are congruent2. Diagonals are perpendicular3. Diagonals bisect corner angles
Square
• Parallelogram that has all of those properties plus combines the properties of a rectangle and a rhombus
Sum of Interior Angles of a Polygon
0( 2)180n −
Sum of Exterior Angles of a Polygon
0360
C i cR L e S
Diameter of a circle
d=2rDiameter Radius
Circumference of a circle
C= 2 rCircumference
Radius
Area of a circle
A= r2 Area Radius
Central Angle
Central Angle
O
Arc of a Circle
Arc
O
Sector
• A sector is a region that is formed between two radii and the arc joining their end points
To find the area of a sector…..
360r2
Area of a Circle
Length of Arc
3602 r
Circumference of a Circle
Sum of all angles in a circle
360o
Tangent to a Circle
• Tangent line is perpendicular to the radius at the point of tangency
Probability
Number of favorable outcomeTotal number of outcomes
Statistics Terms
Average=Mean
the sum of a set of values
the total number of values in the set
Median
Middle number in a set of numbers arranged in numerical order
Mean
average of the middle two numbers
Mode
Values that appear the most often in a set of numbers.
Acute Angles
• Angle whose measure is between 0 and 90 degrees.
Obtuse Angles
• Angle whose measure is between 90 and 180 degrees.
Complementary Angles
• Two angles that sum to 90 degrees.
Right Angle
An angle that is 90 degrees
Supplementary Angles
• Two angles that sum to 180 degrees.
Straight Angle
• An angle that’s measure is 180 degrees
Vertical Angles
• Angles that are opposite of each other when two lines cross • Vertical angles are congruent, so angles a and b are congruent in the image.
Transversal
• A line that crosses two lines (they do not have to be parallel) creating special types of angles
Corresponding Angles
• Angles in matching corners are corresponding. • In this image, a and e, b and f, d and h, d and g are
corresponding.• If the transversal crosses two parallel lines, corresponding angles
are then congruent.
Alternate Interior Angles
• The pairs of angles that are on opposite sides of the transversal but inside the other two lines are alternating interior angles
• In this image, c and f, and d and e are alternating interior.• If the transversal crosses two parallel lines, AI angles are then congruent.
Alternate Exterior Angles
• The pairs of angles that are on opposite sides of the transversal but outside the other two lines are alternate exterior angles
• In this image, a and h, and b and g are alternating interior.• If the transversal crosses two parallel lines, AE angles are then congruent.
Same Side Interior Angles
• Angles that are on the same side of the transversal and on the interior of the other two lines are same side interior.
• In this image, 3 and 6, and 4 and 5 are SSI angles.• If the transversal crosses two parallel lines, SSI angles are
supplementary.
Same Side Exterior Angles
• Angles that are on the same side of the transversal and on the exterior of the other two lines are same side exterior.
• In this image, 2 and 7, and 1 and 8 are SSE angles.• If the transversal crosses two parallel lines, SSE angles are
supplementary.