Question

Consider the function f(x) = 4x2 + 5. Find the value of f(x) when x = 2 and select the correct answer below. A. 13 B. 21 C. 69 D. 89

Answer 1

The answer is B. 21

f(x) = 4(2)^2 + 5
f(x) = 4(4) + 5
f(x) = 16 + 5

f(x) = 21

Answer 2

substitute 2 for x


`f(2)=4(2)^2+5`

`f(2)=4(4)+5`

`f(2)=16+5`

`f(2)=21`

answer is B