SOLUTION: Can someone please help me with this problem? . Evaluate the indicated function. . Find the value of sin (&#945;/2) if cos &#945; = 20/21 and (0DEG < &#945; < 90DEG). . sin(

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Question 643072: Can someone please help me with this problem?
.
Evaluate the indicated function.
.
Find the value of sin (α/2) if cos α = 20/21 and (0DEG < α < 90DEG).
.
sin(α/2)= __?__
Thanks!

Answer by lwsshak3(11628)   (Show Source): You can put this solution on YOUR website!
Find the value of sin (α/2) if cos α = 20/21 and (0DEG < α < 90DEG)
Identity: sin (α/2)=√[(1-cos α)/2]
=√[(1-20/21)/2]
=√[(21/21-20/21)/2]
=√[(1/21)/2]
=√(1/42)
sin(α/2)=√(1/42)

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