I have to find the inverse function of f(x)=3-4x. I got y=3-x/4 for the function. I then have to plug it back into the function and verify that it is the inverse. So I wrote (3-4(3-x))/4. This resulted in (-3+x)/4=x. I tried isolating it to get x=x but I just can't get it. Where did I goof up?

1 answer

if g(x) is the inverse of f(x), then
f(g(x)) should equal x.
You proved that....
f(inverse)=(3-4(3-x))/4=x