# Math Help - Evaluating This Trig Function

1. ## 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)) =

2. 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))

3. 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

4. Draw out your right triangle and work from there. The first term can be found easily this way.

5. 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