Verify: Sin(α/3)Cos(α/3)=.5Sin(2α/3)
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Use the sine double-angle identity.
Originally Posted by eumyang Use the sine double-angle identity. In the second step how did you get Cos to appear?
Like I said, I used the sine double angle identity: . You should have learned this. If not, you could still verify the problem using the sine of a sum identity instead: .
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About LinkBacks &= \tfrac{1}{2}\sin \left(2 \cdot \tfrac{\alpha}{3} \right) \\<br />
&= \tfrac{1}{2} \cdot 2 \sin \left(\tfrac{\alpha}{3} \right) \cos \left(\tfrac{\alpha}{3} \right) \\<br />
&= \sin \left(\tfrac{\alpha}{3} \right) \cos \left(\tfrac{\alpha}{3} \right)<br />
\end{aligned})
Originally Posted by eumyang 
