**Cos 30**

### What is Kos?

Cost (30 t)

The formula for reducing cosine is as follows.

cos (a b) = cos (a) cos (b) + sin (a) sin (b)

So, if we want (30t), we have

cos (30t) = cos (30) cos (t) + sin (30) sin (t)

Cosine of 30 degrees is square of (3) / 2.

The 30 degree pocket is 1/2.

Cos (30 t) = [square root (3) / 2] Cos (t) + (1/2) sin (t)

If we want to cut it into pieces, let's go

cos (30 t) = [sqrt (3) cos (t) + sin (t)] / 2

We need to know what theta is.

However, your teacher wants you to use trigonometric identifiers to add and subtract angles.

cos (A B) = cos (A) Cos (B) + sin (A) sin (B)

cos (30 Y) = cos (30) cos (Y) sin (30) sin (Y) where Y is theta. This

cos (A B) = cos (A) * cos (B) + sin (A) * sin (B)

cos (30 t) = cos (30) * cos (t) + sin (30) * sin (t) = ÂˆÃ‚Âš3 / 2 * cos (t) + sin (t) / 2