PA Test 6 Review - Functions

Continuous Data

A function where the domain can only be in any fractional amount i.e. Time passing, Buying items by pounds, amount of something being eaten

Discrete Data

A function where the domain can only be in whole number intervals. i.e. Slices of Pie, Amount of People, Runs per game

How can you determine a non-linear function from an equation?

Any equation that has an x-value raised to a power that is NOT 1.

How can you determine if a table represents a linear function?

Find the differences in the x and y values, and if there is a consistent change in both variables, then there is a linear function.

How do you write a equation of a function from a graph? (f(x) = mx + b)

Find the y-intercept (b). Find two "nice points" and count the slope between them (m). Plug those values into f(x) = mx + b.

How can you determine a non-linear function from a graph?

Graphs that are NOT straight lines

Write a function that can represent this situation: A store sells steaks at $7.99 per pound.

let x = amount of pounds of steak f(x) = 7.99x (needs to be f(x) b/c you must write a function)

What is another name for rate of change?

slope

How can you find the rate of change from a graph?

Pick two "nice points" and find the slope between them.

How do you find x if given f(x)? i.e. f(5) = -2x + 25

Set -2x + 25=5, and solve for x

How do you interpret the y-intercept?

The initial value of a function

How do you interpret the slope?

The rate of change of a function.

Domain

The set of all input values for a relation or function (the x values) Domain is written with these brackets { }

range

The set of all output values for a function or relation (the y values) Range is written with these brackets { }

What does f(x) mean?

f(x) is equivalent to y, just written in function notation.

Qualitative graph

graphs that are used to represent situations that do not necessarily have numerical values. usually the x-axis is time, and the y-axis is what you are looking at