# trig

Find sin (alpha/2) and cos (alpha/2)

sin alpha = 3, -pi/2 < alpha <less then or equal to 0

How to get the answer of sin (alpha/2) = -1/square root 3, cos(alpha/2) = square root 6/3?

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1. You said "sin alpha = 3"

check your typing, the sine of any angle must be between ±1

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posted by Reiny

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