SOLUTION: State the formula for sin(a + b) and use it to show sin(a + 3π/2) = − cos(a)

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Question 808724: State the formula for sin(a + b) and use it to show sin(a + 3π/2) = − cos(a)
Found 2 solutions by stanbon, lwsshak3:
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
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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Answer by lwsshak3(11628)   (Show Source): You can put this solution on YOUR website!
State the formula for sin(a + b) and use it to show sin(a + 3π/2) = − cos(a)
sin(a+b)=sina*cosb+cosa*sinb
sin(a+3π/2)=sina*0+cosa*-1=-cos(a)

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