# Math Help - What is the exact value of sin(pi/12)

1. ## What is the exact value of sin(pi/12)

What is the exact value of sin(pi/12)

Explain how you get it

2. Originally Posted by skeske1234
Explain how you get it
Explain how one gets what? There is no question in your post.

Are you maybe referring to the contents of your subject line...? If so, then try using the same sort of technique which was provided to you here.

If you get stuck, please reply showing how far you have gotten, starting with how you turned 1/12 into a sum or difference of 1/2, 1/3, 1/4, and / or 1/6, and showing which trig identity you are using. Thank you!

3. I don't know what compound angle formula to use for
sin(pi/12)
because pi/12 = 15 degrees... There is no special angle that will add up to that.
What is another method I could use?

4. So try doing subtractions....

5. Originally Posted by stapel
So try doing subtractions....
OHHHHHHHSDLKJGHDSKJGHSDJ omg . k.

wow -.-

6. Hello,

U have this formula:

$sin^2(x)=\frac{1-cos(2x)}{2}\Rightarrow sin(x)=\sqrt{\frac{1-cos(2x)}{2}}$

$sin(\frac{\pi}{12})=\sqrt{\frac{1-cos(\frac{\pi}{6})}{2}}$

$sin(\frac{\pi}{12})=\sqrt{\frac{1-\frac{\sqrt{3}}{2}}{2}}$

Also u can have the next method

$sin(\frac{\pi}{4}-\frac{\pi}{6})=sin(\frac{\pi}{4})cos(\frac{\pi}{6} )-sin(\frac{\pi}{6})cos(\frac{\pi}{4})$

$sin(\frac{\pi}{4}-\frac{\pi}{6})=\frac{\sqrt{2}}{2}*\frac{1}{2}-\frac{\sqrt{3}}{2}*\frac{\sqrt{2}}{2}$

Have a nice day,

Hush_Hush.