Question

If f(x) = 21 + 3sqrt(x+12)

and g(x) = 2x^2+ 5, compute the composition (f ∘ g)(4).

(f ∘ g)(4) =

sqrt= square root of what’s in ( )

Answer 1

42

Explanation:

g(4) = 2x^2+5

= 2(4)^2+5

= 2(16)+5

= 32+5

= 37

f(g(4)) = 21+3sqrt(x+12)

= 21+3sqrt(37+12)

= 21+3sqrt(49)

= 21+3(7)

= 21+21

= 42