1. ## Simplification, Half Angles?

I am COMPLETELY lost with this problem.. Ive tried to get help from a number of people and no one seems to be able to help. Here is the problem, if it could be worked out and explained i would greatly appreciate it. Can't even find similar problems in my book.

Square root of 1-cos(12B)/2

I am COMPLETELY lost with this problem.. Ive tried to get help from a number of people and no one seems to be able to help. Here is the problem, if it could be worked out and explained i would greatly appreciate it. Can't even find similar problems in my book.

Square root of 1-cos(12B)/2
Is it
$\sqrt{1-\frac{\cos (12B)}{2}}$

or more likely,
$\sqrt{\frac{1-\cos (12B)}{2}}$?

3. Originally Posted by Gusbob
Is it
$\sqrt{1-\frac{\cos (12B)}{2}}$

or more likely,
$\sqrt{\frac{1-\cos (12B)}{2}}$?

The 2nd one, sorry I dont know how to input math problems like that hah.

$\sqrt{\frac{1-\cos(12B)}{2}}$ = $\sqrt{\frac{1-\cos(2(6B))}{2}}$
Now $\cos 2\theta = 1 - 2\sin ^2 \theta$. Apply this to cos 12B with $6B = \theta$