SOLUTION: Find the exact value of the following expression... cos(sin^-1(3/5) + cos^-1(5/13))

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Question 882470: Find the exact value of the following expression...
cos(sin^-1(3/5) + cos^-1(5/13))

Found 2 solutions by stanbon, lwsshak3:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find the exact value of the following expression...
cos(sin^-1(3/5) + cos^-1(5/13))
=====
cos(36.87 deg + 67.38 deg) = cos(104.25) = -0.2462
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Cheers,
Stan H.

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Find the exact value of the following expression...
cos(sin^-1(3/5) + cos^-1(5/13))
***
let x=angle whose sin=3/5
sinx=3/5
cosx=4/5
..
let y=angle whose cos=5/13
cosy=5/13
siny=12/13
..
cos(sin^-1(3/5) + cos^-1(5/13))=cos(x+y)=cosxcosy-sinxsiny
cos(x+y)=4/5*5/13-3/5*12/13=20/65-36/65=-16/65