Math - Precalculus Flashcards
What are the set of numbers?
Natural number (counting numbers from 1 to infinity)
Integers (Includes natural numbers, zero and negative natural numbers)
Rational numbers (ratio of integers)
Irrational numbers (cannot be represented as a ratio of integers)
Real numbers (all numbers)
What is the commutative property of addition?
The order of the terms doesn’t matter.
What is the associative property of multiplication and addition?
You can put parentheses anywhere.
Vertical shifting: How to shift the graph of a function up or down?
To shift up, you add a constant (y = x^2 + c)
To shift down, you substract a constant (y = x^2 - c)
Horizontal shifting: How to shift the graph of a function to the left or right?
To shift left, you add to x (y = (x + c)^2 )
To shift right, you substract from x (y = (x - c)^2)
Reflecting: How to reflect a graph on the x or y axis?
To reflect a function on the x axis: f(x) = -f(x)
To reflect a function on the y axis: f(x) = f(-x)
Vertical stretching: how to stretch the graph of a function?
mutiply the function by a constant > 1: 2f(x)
Vertical shrinking: how to shrink a function?
mutiply the function by a constant > 0 and < 1: 0.5f(x)
Horizontal stretching: how to stretch a function?
multiply x by a constant > 0 and < 1: f(0.5x)
Horizontal shrinking: how to shrink a function?
multiply x by a constant > 1: f(2x)
What is an even function?
A function whose graph is symmetric at the y axis.
This function statisfies: f(-x) = f(x)
What is an odd function?
A function whose graph is symmetric at the origin.
This function satisfies: f(-x) = -f(x)
When do you switch the sign of an inequation?
When multiplying or dividing by a negative number.
What is a one to one function?
f^-1(f(x)) = x
How to inverse a function?
Isolate x in the function so that x = f(y)
What is the formula to find vertexes of a quadratic function?
a(x - h)^2 + k
What does it mean if in a(x - h)^2 + k, a < 0?
Then f(h) = k is the maximum.