SOLUTION: If and sin∝=4/5, and ∝ is an acute angle, find the exact value of sin 2∝

Question 1171118: If and sin∝=4/5, and ∝ is an acute angle, find the exact value of sin 2∝
Answer by ikleyn(52776) (Show Source): You can put this solution on YOUR website!
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If and sin(a)=4/5, and "a" is an acute angle, find the exact value of sin 2a.
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If sin(a) = ,  then cos(a) =  =  =  =  = .


and we use the positive value of the square root, since the angle "a" is acute.


Next,  sin(2a) = one of the basic formula of Trigonometry = 2*sin(a)*cos(a) =  = .    ANSWER

Solved.

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