SOLUTION: Please help me: 2. If cos x=1/2, then sin x= ? 3. If cotx=1, then x= ? Thanks

Algebra ->  Trigonometry-basics -> SOLUTION: Please help me: 2. If cos x=1/2, then sin x= ? 3. If cotx=1, then x= ? Thanks      Log On


   



Question 383471: Please help me:
2. If cos x=1/2, then sin x= ?
3. If cotx=1, then x= ?
Thanks

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
2. If cos x=1/2, then sin x= ?
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If cos(x) = 1/2 then x=1 and r = 2
Then y = sqrt(r^2-x^2) = sqrt(4-1) = sqrt(3)
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But y can be positive or negative.
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So sin(x) = y/r = sqrt(3)/2 or sin(x) = y/r = -sqrt(3)/2
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3. If cotx=1, then x= ?
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x = 45 degrees or x = 180+45 = 225 degrees
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Cheers,
Stan H.