SOLUTION: Need help with question please; Given; sin (x+y) = sin x cos y+ cos x sin y and cos (x +y) =cos x cos y - sin x sin y. Solve algebraically ; cos (x+90degrees) = 2 sin ^2 x - pi/2
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-> SOLUTION: Need help with question please; Given; sin (x+y) = sin x cos y+ cos x sin y and cos (x +y) =cos x cos y - sin x sin y. Solve algebraically ; cos (x+90degrees) = 2 sin ^2 x - pi/2
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Question 984824: Need help with question please; Given; sin (x+y) = sin x cos y+ cos x sin y and cos (x +y) =cos x cos y - sin x sin y. Solve algebraically ; cos (x+90degrees) = 2 sin ^2 x - pi/2 < x < pi/2. Answer by solver91311(24713) (Show Source):
You should get used to using radians instead of degrees.
Use the unit circle to find the angle whose sine is negative 1/2 in the given interval. Negative angles are measured clockwise from the positive x-axis.
John
My calculator said it, I believe it, that settles it
