Question

Given f(x) = 2x^2+4x−6, evaluate f(−2).

a) 2
b) -6
c) -2
d) 10

Answer 1

b) -6

Explanation:

`f(x) = 2x^2+4x-6\\\\f(-2) = ?\\\\`

Substitute ; -2 for x in the given equation

`f(-2) = 2(-2)^2 +4(-2)-6\\\\f(-2) =2*\:4+4\left(-2\right)-6\\\\f(-2) =8+4\left(-2\right)-6\\\\f(-2) =8-8-6\\\\f(-2) = -6`

Answer 2

-6

Explanation:

f(x) = 2x^2+4x−6

Let x = -2

f(-2) = 2(-2)^2+4(-2)−6

= 2 (4) -8 -6

= 8-8-6

=-6