If f(x) = 1 2 x – 1 and g(x) = x 2 - 1 , find ( f ( g ( 3 ) ) =

Question

if f(x)=1/2x-1 and g(x)=x² -1, find (f(g(3))

Answer 1

These always used to confuse me, too. We work inside out.

 

Hopefully you know how to find g(3).

 

g(3) = 3² - 1

g(3) = 9 - 1

g(3) = 8

 

f(8) = (1/2)8 - 1

f(8) = 4 - 1

f(8) = 3

 

Another more complicated way...

 

f(g(3)) = (1/2)(3² - 1) - 1

f(g(3)) = (1/2)(9 - 1) - 1

f(g(3)) = (1/2)(8) - 1

f(g(3)) = 4 - 1

f(g(3)) = 3