theorems Flashcards
function
A function f consists of a set of inputs, a set of outputs, and a rule for assigning each input to exactly one output. The
set of inputs is called the domain of the function. The set of outputs is called the range of the function.
vertical line test
Given a function f , every vertical line that may be drawn intersects the graph of f no more than once. If any vertical
line intersects a set of points more than once, the set of points does not represent a function.
when we have a graph that’s symmetric with respect to the y axis, we would call it
even
x -intercept
let y be zero and solve equation for x
y-intercept
let x be zero and solve equation for y
symmetry of a graph
There three types of symmetry
- symmetric with respect to the y-axis. this mean the portion of the graph in the y-axis is the mirror image of the portion of the graph in the y-axis
- symmetric with respect to the x-axis this mean the portion of the graph in the x-axis is the mirror image of the portion of the graph in the x axis
- symmetric with respect to the origin
Symmetry theorem
- The graph of an equation in x and y is symmetric with respect to the y-axis when replacing x by -x yields an equivalent equation
- The graph of an equation in x and y is symmetric with respect to the x-axis when replacing y by -y yields an equivalent equation
- The graph of an equation in x and y is symmetric with respect to the origin when replacing x by -y and y by -y yields and equivalent eqation .
symmetric to the y test - just change the x to -x
symmetric to the x test - just change the y to -y, which makes the whole function negative
The graph of a polynomial has symmetry with respect to the y-axis when each term has
even exponent (constant) y=2x^4-x^2+2
the graph of a polynomia has a symmetry with respect to the origin when each term has an
odd exponent
even function test
f(-x)=f(x), the graph of cos and sec
odd function test
f(-x)=-f(x) the graph of sin, tan, cot, and csc
inverse function test
f(g(x))= g(f(x)) = x, they both had yeild the same value
vertical line test
Given a function f , every vertical line that may be drawn intersects the graph of f no more than once. If any vertical
line intersects a set of points more than once, the set of points does not represent a function.
if a graph does not pass a vertical line test, then that graph is not a function
to find the zeros of a function
just make f(x) equal to zero and solve for the x
for example:
find the zeros of f(x)=x^2+2
x=(x)^1/2
three scenarios limit does not exist
- Asymptotes
- break and jump
- biesce wise function