Big Ideas Math Integrated I, 2016
BI
Big Ideas Math Integrated I, 2016 View details
3. Function Notation
Continue to next subchapter

Exercise 6 Page 125

To evaluate a function for a given value of the variable, substitute the value for the variable.

-5, -7, and -12

Practice makes perfect
To evaluate a function for a certain value of x means that we substitute the given value for every instance of x. Let's do this for the given function when x=-2.
r(x)=- x-7
r( -2)=-( -2)-7
r(-2)=2-7
r(-2)=-5
When x=-2, the function's value is -5. We will evaluate this function for x=0 and x=5 in the same way using the table below.
x - x-7 r(x)
-2 -( -2)-7 -5
0 - 0-7 -7
5 - 5-7 -12