# More Simplifying

• January 12th 2010, 10:49 PM
Paymemoney
More Simplifying
Hi
I need help on the following questions:
Simplify the following expression in an exact form: $cos(sin^{-1}\frac{4}{5})$

P.S
• January 12th 2010, 11:49 PM
bigwave
exact form
$\cos\left(\sin^{-1}\left(\frac{4}{5}\right)\right) = \frac{3}{5}$
• January 13th 2010, 12:27 AM
Paymemoney
can this be done without using the calculator??
• January 13th 2010, 12:44 AM
bigwave
you are looking at a 3,4,5 triangle
• January 13th 2010, 01:39 AM
Paymemoney
ok ic