SOLUTION: complete: sin 225 cos 90 - cos 225 sin 90 =
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Question 898329: complete: sin 225 cos 90 - cos 225 sin 90 =
Found 2 solutions by stanbon, josmiceli:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
complete: sin 225 cos 90 - cos 225 sin 90
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(-sqrt(2)/2)(0) - (-sqrt(2)/2)*(1)
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= sqrt(2)/2
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Cheers,
Stan H.
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Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
The problem reduces to:
The cosine is negative in the 3rd quadrant, so
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