# Evaluating This Trig Function

• Mar 26th 2006, 05:17 PM
drewms64
Evaluating This Trig Function
Hi, I was wondering if anyone could help me evaluate this trig function

sin(Cos^-1(5/13) + Sin^-1(3/5)) =
• Mar 26th 2006, 07:27 PM
drewms64
would this be working it to the right way?

using the Sum and Differences forumla of
sin(x+y)=sinXcosY+cosXsinY

Sin(Cos^-1(5/13))Cos(Sin^-1)) + Cos(Cos^-1(5/13))Sin(Sin^-1(3/5))
• Mar 27th 2006, 03:53 AM
topsquark
Quote:

Originally Posted by drewms64
would this be working it to the right way?

using the Sum and Differences forumla of
sin(x+y)=sinXcosY+cosXsinY

Sin(Cos^-1(5/13))Cos(Sin^-1)) + Cos(Cos^-1(5/13))Sin(Sin^-1(3/5))

Looks like a good start to me!

-Dan
• Mar 27th 2006, 03:28 PM
Jameson
Draw out your right triangle and work from there. The first term can be found easily this way.
• Apr 3rd 2006, 03:20 PM
drewms64
I was able to use the right triangle way and get

Code:

```SIN(COS^-1(5/13))COS(SIN^-1(3/5)) + (5/13)(3/5) (12/13)(4/5) + (5/13)(3/5) (48/65) + (15/65) = 63/65```
thanks for the help