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by **anonmeans** on Fri Mar 06, 2009 5:36 pm

Find the exact value of $sin(\frac{3\pi}{8}$

Since $\frac{3\pi}{8} = (\frac{1}{2}) (\frac{3\pi}{4})$ , can I use the half angle formula?

$sin(\frac{3\pi}{8}) = \pm \sqrt{ \frac{1-cos(\frac{3\pi}{4})} {2} }$

Do i use the "+" because of $\frac{3\pi}{8}$ being in Q!?

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by **stapel_eliz** on Fri Mar 06, 2009 7:58 pm

anonmeans wrote:Find the exact value of $sin(\frac{3\pi}{8}$

Since $\frac{3\pi}{8} = (\frac{1}{2}) (\frac{3\pi}{4})$ , can I use the half angle formula?

Yes, that would be the way to go. And yes, use the positive square root!

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Find the exact value of [tex]sin(\frac{3\pi}{8}[/tex]

Find the exact value of [tex]sin(\frac{3\pi}{8}[/tex]