SOLUTION: Given f(x)=x^2-4, find f^-1(x) and determine necessary restriction so that f^-1(x) is a function

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Question 881391: Given f(x)=x^2-4, find f^-1(x) and determine necessary restriction so that f^-1(x) is a function
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Use x,y notation.
y=x%5E2-4
Interchange x and y and solve for y.
This new y is the inverse.
x=y%5E2-4
y%5E2=x%2B4
y=0+%2B-+sqrt%28x%2B4%29
In order for y to be a function, x%2B4%3E=0 since the square root is only defined for non-negative values.
x%2B4%3E=0
x%3E=-4