SOLUTION: Given: A is a positive acute angle and cosA = 4/5. Find the exact value of sin(x + pi/2).

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Question 746469: Given: A is a positive acute angle and cosA = 4/5.
Find the exact value of sin(x + pi/2).
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Given: A is a positive acute angle and cosA = 4/5.
Find the exact value of sin(x + pi/2).
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sin(x+(pi/2)) = sinx*cos(pi/2)+cos(x)*sin(pi/2)
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= sin(x)*0 + cos(x)*1)
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= 0 + cos(x)
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= cos(x)
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Cheers,
Stan H.