Question

If f(x)=x+7 and g(x)=x-7
(a) f(g(x)=_______
(b) g(f(x)=_______
(c) thus g(x) is called an inverse function of f(x)
CAN I GET HELP ON THIS?

Answer 1

f(g(x)) = g(x) + 7
= (x-7) + 7
= ?

Answer 2

f(g(x)) = (x-7) +7 = x
g(f(x)) = (x+7) -7 = x

Answer 3

so f(g(x))= (x-7)+7

Answer 4

for f(g(x)), you plug in g(x) into f(x)

Answer 5

You can then remove the ( ) and simplify further.

Answer 6

And part c isnt really a problem, its just true

Answer 7

i got (c) right, it is called an inverse, (a) is then (x-7)(x+7) and converts to x^2-49 then?

Answer 8

thats f(x)*g(x)

Answer 9

but yea your (x-7)(x+7) = x^2 -49

Answer 10

cause i typed in that last part into my web homework and got it wrong, it isnt x^2-49

Answer 11

thats because part a asks for f(g(x)). thats different than f(x)*g(x)

Answer 12

so (a) is then (x-7)+7 and (b) is then (x+7)-7 ??

Answer 13

yes. and they both are equal to x

Answer 14

ok thank you a bunch

Answer 15

no problem