Posted by Sara on Wednesday, January 11, 2012 at 9:10am.
verify that the function f and g are inverse of each other by showing f(g(x)) and g(f(x)) =x
f(x)= 62/5x g(x)=155/2x

math  Steve, Wednesday, January 11, 2012 at 5:30pm
just plug and chug:
(I rewrite 2/5x as 2x/5 to avoid ambiguity)
f(g) = 6  2g/5 = 6  2(15  5x/2)/5
= 6  (30  5x)/5 = 6  (6  x) = x
g(f) = 15  5f/2 = 15  5(6  2x/5)/2
= 15  (30  2x)/2 = 15  (15  x) = x