SOLUTION: If f(x) = (x + 48.2)3, what does f−1(−8) equal?

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Question 132987: If f(x) = (x + 48.2)3, what does f−1(−8) equal?


Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Based on your recent note, the problem is asking for the inverse function of
f%28x%29+=+%28x+%2B+48.2%29%5E3
First, replace f%28x%29 with y.
y+=+%28x+%2B+48.2%29%5E3
Now, solve for x.
cuberoot%28y%29+-48.2+=+x
Reorder as
x+=+cuberoot%28y%29+-48.2
Finally, replace every x with y and every y with x as follows:
y+=+cuberoot%28x%29-48.2
That is the inverse function

Now solve when x = (-8)
y+=+cuberoot%28x%29+-48.2
y+=+cuberoot%28-8%29+-+48.2
y+=+-2+-+48.2
y = -50.2