kinuel8091
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- Jul 27, 2013
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i have no idea how to solve this. help please 
Help trigo!
- Thread starter kinuel8091
- Start date
The sum of two angles is pi/4.
I assume you recognize (draw it on a unit circle if you didn't!) that if the sine is 3/5, then the cosine of that angle is 4/5. Also you should recognize that sin(pi/4) = cos(pi/4) = sqrt(2)/2.
Solve for \(\displaystyle \cos^{-1}x\). Then take the cosine of both sides using the difference-of-angles formula.
If you need more help, show us your work.
- Joined
- Feb 4, 2004
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When you say you "have no idea how to solve this", are you saying that you need lessons on inverse trig functions? On solving trig equations? On trig functions? On trig identities?
How far back are you needing the lessons to start? Please be specific. Thank you.