Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
3. Function Notation
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Exercise 4 Page 125

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

-6, 0, and 15

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.
g(x)=3x
g( -2)=3( -2)
g(-2)=-3 * 2
g(-2)=-6
When x=-2, the function's value is -6. We will evaluate this function for x=0 and x=5 in the same way using the table below.
x 3x g(x)
-2 3( -2) -6
0 3( 0) 0
5 3( 5) 15