(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Find the exact value of : sin[sin^-1 (3/5) - cos^-1 (-4/5)]

2. Relevant equations

sin(A-B) = sinA*cosB-cosA*sinB

3. The attempt at a solution

sin A = (3/5) sin B = (-3/5)

cos A = (4/5) cos B = (-4/5)

(3/5)*(-4/5) - (-3/5)(4/5)

(-12/25) - (-12/25) = 0

I did that and the book says that the answer is (-24/25). What did I do wrong?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Difference Formula Involving Inverse Trgi Functions

**Physics Forums | Science Articles, Homework Help, Discussion**