SOLUTION: Given f(x)=3x+4 Find f -1(x)

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Question 56080: Given f(x)=3x+4
Find f -1(x)
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
There are a few different ways to do this, and I don't want to conflict with your teacher or your textbook, but I like to find the inverse function in TWO steps: 1. Interchange the x and y, and 2. Solve for y.

So, y = 3x+4

Step 1: Interchange the x and y:
x= 3y +4

Step 2: Solve for y:
x-4 = 3y

Divide both sides by 3:
%28x-4%29%2F3=+y.

So, y+=+f%5E%28-1%29%28x%29+=+%28x-4%29%2F3 or +%28x%2F3%29-%284%2F3%29+

R^2 at SCC