SOLUTION: If f(x)={{{x^3+1}}} and {{{f^-1}}} is the inverse function of f, what is {{{f^-1}}}(4)?

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Question 551020: If f(x)=x%5E3%2B1 and f%5E-1 is the inverse function of f, what is f%5E-1(4)?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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If f(x)=x%5E3%2B1 and f%5E-1 is the inverse function of f, what is f%5E-1(4)?
y = f(x)
y = x^3 + 1
Find the inverse equation, replace x with y, solve for y
x = y^3 + 1
x - 1 = y^3
y = 3sqrt%28x-1%29; that's the cube root of (x-1)
when x = 4
y = 3sqrt%284-1%29;
y = 3sqrt%283%29;
or
y = 3%5E%281%2F3%29
f%5E-1(4) = 1.44225