# Thread: Inverse function of this one...

1. ## Inverse function of this one...

Hi,
does anybody know how to find out the "inverse" function of this function:

$\displaystyle f(x) = 3 + \arcsin (2x + 1)$

I have absolutely no idea how to start.
Any help is welcome.

Thanks.

2. Originally Posted by petike
Hi,
does anybody know how to find out the "inverse" function of this function:

$\displaystyle f(x) = 3 + \arcsin (2x + 1)$

I have absolutely no idea how to start.
Any help is welcome.

Thanks.
no surprises here. as always, to find the inverse function, switch x and y and solve for y

3. ## But what then?

Originally Posted by Jhevon
no surprises here. as always, to find the inverse function, switch x and y and solve for y
Ok, so I know how to start.
But what then. I know I should make $\displaystyle y$ alone. But how?
I would like to see the whole process of that.

Thanks anyway.

4. Originally Posted by petike
Ok, so I know how to start.
But what then. I know I should make $\displaystyle y$ alone. But how?
I would like to see the whole process of that.

Thanks anyway.
note that if $\displaystyle \theta = \arcsin \varphi$, then $\displaystyle \sin \theta = \varphi$

now can you try?

5. ## Thanks

Originally Posted by Jhevon
note that if $\displaystyle \theta = \arcsin \varphi$, then $\displaystyle \sin \theta = \varphi$

now can you try?
Ah, thanks,
now it's clearer.

You've got my thanks.