Question

Find the value of f(–3) and g(3) if f(x) = –6x + 3 and g(x) = 3x + 21x^–3.

f(–3) = 21 g(3) = 9.78
f(–3) = –18 g(3) = –9.78
f(–3) = –3 g(3) = 30.04
f(–3) = 15 g(3) = 8.22

Answer 1

f(-3)=21

Explanation:

Plug in -3 for x. -6•-3=18. 18+3=21.

Answer 2

f(–3) = 21 g(3) = 9.78

Explanation:

Given functions,

`f(x) = -6x + 3-----(1)`

`g(x)=3x+21x^(-3)-----(2)`

Put x = -3 in equation (1),

`f(3) = -6(-3) + 3 = 18 + 3 = 21`

Put x = 3 in equation (2),

`g(3) = 3(3) + 21 (3)^(-3)=9 + (21)/(3^3)=9+(21)/(27)=9.777778\approx 9.78`

Hence, first option is correct.