SOLUTION: Suppose that sin(t)=7/25 where t is in the 1st quadrant. Find cos(2t). Help please and show an example with numbers please the words are what confuse me in the 1st place!

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Question 762241: Suppose that sin(t)=7/25 where t is in the 1st quadrant. Find cos(2t). Help please and show an example with numbers please the words are what confuse me in the 1st place!
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose that sin(t)=7/25 where t is in the 1st quadrant. Find cos(2t). Help please and show an example with numbers please the words are what confuse me in the 1st place!
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cos%28t%29=sqrt%281-sin%5E2%28t%29%29
cos%28t%29=sqrt%281-49%2F625%29
cos%28t%29=sqrt%28576%2F625%29=24%2F25
Identity: cos(2t)=cos^2(t)-sin^2(t)=576/625-49/625=527/625
Calculator check:
sin(t)=7/25
t≈16.26º
2t≈32.52º
cos(2t)=cos(32.52º)≈0.8432
exact value=527/625≈0.8432