Question

Evaluate the function.

f
(
x
)
=
2
x
2
+
8
x
f(x)=2x
2
+8x
Find
f
(
−
1
)
Find f(−1)

Answer 1

-12

Explanation:

f ( x) = 2 x 2 + 8 x

Find f(−1)

replace x by its value which is -1

so:

f ( x) = 2 x 2 + 8 x

f ( -1) = 2 (-1)*2 + 8 (-1)

f(-1)= -2*2 + (-8)

f(-1)= -4 -8

f(-1)= -12