# I have a sine question!

• Jun 26th 2008, 12:25 PM
Darkhrse99
I have a sine question!
How does $sin\frac{7pi}{12} = sin(\frac{Pi}{4} +\frac{Pi}{3})$

Do you find factors of 12 which are 3 and 4? What do you do with the $7pi$?

Thanks
Jason
• Jun 26th 2008, 12:29 PM
Chris L T521
Quote:

Originally Posted by Darkhrse99
How does $sin\frac{7pi}{12} = sin(\frac{Pi}{4} +\frac{Pi}{3})$

Do you find factors of 12 which are 3 and 4? What do you do with the $7pi$?

Thanks
Jason

$\sin\left(\frac{7\pi}{12}\right)=\sin\left(\frac{3 \pi+4\pi}{12}\right)=\sin\left(\frac{3\pi}{12}+\fr ac{4\pi}{12}\right)=\color{red}\boxed{\sin\left(\f rac{\pi}{4}+\frac{\pi}{3}\right)}$

Does this make sense?

--Chris
• Jun 26th 2008, 12:34 PM
Darkhrse99
that was easy! I can't believe I didn't see that(Headbang)