Question

Find f^-1 for the function f(x)=(1/3)x^3+(5/3)x+2

Answer 1

good luck

Answer 2

i am going to make a guess that the actual question had to do with finding the derivative of the inverse at a point
of course that is just a guess, so i could be wrong

Answer 3

ah my bad, u're right, it's (f^-1)'

Answer 4

how'd i guess?

Answer 5

you do not have to find the inverse for this, so don't even try it
what is the number
i assume it is not "find \((f^{-1})'(x)\) but rather find \((f^{-1})'(a)\) for some \(a\)

Answer 6

yes u're right >,< but because I just want to know how to find the inverse?

Answer 7

like i said, good luck with that program
it is not going to work
you are not going to solve a cubic equation for \(y\)
what number is it? i can show you how to solve the problem
the question is not about finding the inverse of the function

Answer 8

the number is 12

Answer 9

whew now we can do it!

Answer 10

\[\left(f^{-1}\right)'(12)=\frac{1}{f'(f^{-1}(12))}\] so you need two numbers, namely \(f^{-1}(12)\) and \(f'(that)\)

Answer 11

\(f^{-1}(12)\) you find by inspection
i.e. guess at a solution to \[\frac{1}{3}x^2+\frac{5}{3}x+2=12\]

Answer 12

typo there\[\frac{1}{3}x^3+\frac{5}{3}x+2=12\]

Answer 13

oh damn no, i cannot solve it
did i read the function correctly, or did i make a typo?

Answer 14

the function is correct, it's here
http://i.imgur.com/bpWLqsv.png

Answer 15

yeah i see that
i am going to guess there is a mistake somewhere in the question
you do not know how to solve \[\frac{1}{3}x^3+\frac{5}{3}x+2=12\]

Answer 16

usually the problem is cooked up so the answer is obvious, but not in this case
you would have to solve a cubic equation