Question

Evaluate (f + g)(x) if f(x) = 2x^2 and g(x) = 3x – 2 when x = 3.

Answer 1

(f + g)(3) = 22.

Explanation:

Given the following function operations:

(f + g)(x) if f(x) = 2x² and g(x) = 2x - 2, and that x = 3:

The function operation can also be expressed as follows:

(f + g)(x) = f(x) + g(x)

We could simply perform the required function operations separately, then add their results in the end. Substitute the value of x = 3 as an input into f(x) and g(x):

f(x) = 2x²

f(3) = 2(3)² = 2(9) = 18

Hence, f(3) = 18

g(x) = 2x - 2

g(3) = 2(3) - 2

g(3) = 6 - 2 = 4

g(3) = 4

(f + g)(x) = f(x) + g(x)

(f + g)(3) = f(3) + g(3)

(f + g)(3) = 18 + 4

(f + g)(3) = 22

Therefore, (f + g)(3) = 22.