## Trigo equations help!

Trigonometric ratios and functions, the unit circle, inverse trig functions, identities, trig graphs, etc.

### Trigo equations help!

I have no idea how to do this

$\sin^{-1}\left(\frac{3}{5}\right)\, +\, \cos^{-1}(x)\, =\, \frac{\pi}{4}$

kinuel8091

Posts: 1
Joined: Wed Sep 18, 2013 12:41 pm

Posted edited to remove hotlink from other site.

stapel_eliz

Posts: 1797
Joined: Mon Dec 08, 2008 4:22 pm

### Re: Trigo equations help!

FYI: Linking images from other sites (other than image-storage sites) is sometimes thought of as being "hostile" to the other site. It might be better to use the LaTeX formatting here (I've used it to replace your graphic) or web-safe text formatting instead. Thanks!

kinuel8091 wrote:I have no idea how to do this

$\sin^{-1}\left(\frac{3}{5}\right)\, +\, \cos^{-1}(x)\, =\, \frac{\pi}{4}$

I'm sorry you missed the classes where they covered this. To make up, you can try online lessons like these for learning how to solve inverse trig equations. Once you've got some of the basics, then please try this problem. Keep in mind that the inverse sine is some angle (call it A) and the inverse cosine is another angle (call it B) so the (say) cosine of the whole thing is cos(A + B) = cos(pi/4) = 1/sqrt(2). And you can do identities to simplify the sum.

maggiemagnet

Posts: 289
Joined: Mon Dec 08, 2008 12:32 am