Question

Let f(x) = x^2 + 6 and g(x) = x+8/x. Find (g ° f)(-7)

Answer 1

Short Answer: 55.145454545...
Working Out: gof(x) = (x^2 + 6) + 8/(x^2 + 6)
gof(-7) = ((-7)^2 + 6) + 8/((-7)^2 + 6)
= (49 + 6) + 8/(49 + 6)
= 55 + 8/55
= 55 + 0.145454545...
= 55.145454545...

Answer 2

(g o f)(x)=g(f(x))

basically put f(x) for every x in g(x) or evaluate f(x) for taht given value of x and then sub that for x in g(x)
evaluate woould be easier
f(-7)=(-7)^2+6
f(-7)=49+6
f(-7)=55

sub for x in g(x)
g(55)=55+8/55
g(55)=63/55
g(55)=1.145454545454

answer would be 63/55