Inverse Function with multiple x terms.

**mattty** · March 22nd 2009, 09:56 PM

Hi I'm trying to find the inverse function of $f(x) = 8+x^2+tan{\frac{\pi*x}{2}}$ where $-1< x <1$ and $f^{-1}(8)$
The main place i am having trouble is I don't know how to rearrange for x when there is more than 1 x term. The best I've done is; by letting $f(x)= y$ , get the equation $y-8=x^2+tan{\frac{\pi*x}{2}}$ which doesn't seem to be a great deal better.

Any ideas would be greatly appreciated.

**Jhevon** · March 22nd 2009, 10:07 PM

Originally Posted by mattty

Hi I'm trying to find the inverse function of $f(x) = 8+x^2+tan{\frac{\pi*x}{2}}$ where $-1< x <1$ and $f^{-1}(8)$
The main place i am having trouble is I don't know how to rearrange for x when there is more than 1 x term. The best I've done is; by letting $f(x)= y$ , get the equation $y-8=x^2+tan{\frac{\pi*x}{2}}$ which doesn't seem to be a great deal better.

Any ideas would be greatly appreciated.

please state the problem in its entirety. i suspect that what you were asked to find is something along the lines of $\frac d{dx}f^{-1}(8)$ , in which case, finding the inverse function is not necessary. if all you are after is $f^{-1}(8)$ , finding the inverse function is still not necessary

**mattty** · March 22nd 2009, 10:20 PM

If

, where

, find

.
That is the question verbatim. If finding the inverse function is not necessary then would you mind giving any hints as to the path i should be taking then? It wouldn't be as simple as letting $f(x)=8$ would it? and then since we know that x is between -1 and 1 sub 0 in and $f^{-1}=0$

If it's that simple I will quite happily kick myself

**Jhevon** · March 22nd 2009, 10:20 PM

Originally Posted by mattty

If

, where

, find

.
That is the question verbatim. If finding the inverse function is not necessary then would you mind giving any hints as to the path i should be taking then? It wouldn't be as simple as letting $f(x)=8$ would it? and then since we know that x is between -1 and 1 sub 0 in and $f^{-1}{\color{red}(8)}=0$

If it's that simple I will quite happily kick myself

start kicking

**mattty** · March 22nd 2009, 10:28 PM

le sigh, thanks a bunch

Thread: Inverse Function with multiple x terms.

LinkBack

Thread Tools

Display

Inverse Function with multiple x terms.

Similar Math Help Forum Discussions

Inverse in terms of minors and determinants

Multiple solutions for limit of an inverse function without a calculator

secant inverse in terms of cosine inverse?

Inverse function, in terms with another inverse function

Inverse of a Multiple Variable Function

Search Tags