SOLUTION: Let sin(A) = 3/5 with A in QII. Find the exact value of sin(2A) using an identity.
a. -12/25
b.-24/25
c.24/25
d. None of the above
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-> SOLUTION: Let sin(A) = 3/5 with A in QII. Find the exact value of sin(2A) using an identity.
a. -12/25
b.-24/25
c.24/25
d. None of the above
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Question 680074: Let sin(A) = 3/5 with A in QII. Find the exact value of sin(2A) using an identity.
a. -12/25
b.-24/25
c.24/25
d. None of the above Answer by lwsshak3(11628) (Show Source):
You can put this solution on YOUR website! Let sin(A) = 3/5 with A in QII. Find the exact value of sin(2A) using an identity.
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sinA=3/5 (you are working with a 3-4-5 right triangle)
cosA=-4/5
Identity:
sin2A=2sinAcosA
=2*(3/5)*(-4/5)
=-24/25 (ans b)
..
check: with calculator
A=arcsin(3/5)=143.13º (in QII)
2A=286.26º
sin2A=sin(286.26)≈-0.96
-24/25=-0.96
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