Question

If f(x) = 4 - x2 and g(x) = 6x, which expression is equivalent to (g-1)(3)?

A. 6-3-(4+3)^2

B. 6-3-(4-3)^2

C. 6(3)-4+3^2

D. 6(3)-4-3^2

Answer 1

For this case we have the following functions:

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

We must find
`(g-f) (3)`.

By definition we have to:

`(g-f) (x) = g (x) -f (x)`

So:

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

So, we have to for
`x = 3:`

`(g-f) (3) = 6 (3) -4+ (3) ^ 2`

Answer:

The correct option is C

`6 (3) -4+ (3) ^ 2`