Question 808724
 State the formula for sin(a + b) and use it to show sin(a + 3π/2) = − cos(a)
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sin(a + b) = sin(a)cos(b) + cos(a)sin(b)
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sin(a+(3pi/2)) sin(a)cos(3pi/2) + cos(a)(sin(3pi/2))
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= (sin(a))*0 + cos(a)(-1)
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= 0 - cos(a)
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= -cos(a)
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Cheers,
Stan H.
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