Question

Evaluate the function f(x)=3x 2 −9 for the values listed below
f(-7)= _?

Answer 1

f(- 7) = 138

Explanation:

to evaluate f(- 7) , substitute x = - 7 into f(x)

f(x) = 3x² - 9 , then

f(- 7) = 3(- 7)² - 9 = 3(49) - 9 = 147 - 9 = 138