# Sin Pi 3

## Sin Pi 3

### Help with trigonometric identification? Sin 2pi / 3 = Sin pi / 3?

Try a = pi / 3 and b = pi / 3. 2pi / 3 = a + b, and you can apply your formula. Another piece of information you need here: cos (pi / 3) has a knowledge value that you can use.

Sin (pi / 3) = ÂˆÂš3 / 2.

Sin (2pi / 3)

= Sin (pi / 3 + pi / 3)

= Sin (pi / 3) cos (pi / 3) + cos (pi / 3) sin (pi / 3)

= 2 sins (pi / 3) cos (pi / 3)

= 2 * -3/2 * 1/2.

= 3/2.

Sin 2pi / 3 = 2sin (pi / 3) cos (pi / 3) = 2 x (0.5) x sin (pi / 3) = sin pi / 3

Congratulations.

## Sin Pi 3

Help with triangular ideas? Sin 2pi / 3 = Sin pi / 3? 3

Use the compound angle formula to show that sin 2pi / 3 is the same as sin pi / 3.

idk w To solve this I know you need to use sin (a + b) = sin a cos b + cos a sin b but I can't use it

update

Haha thanks you completely forgot that I can make 1/2 subtitles for cos pi / 3.

Try taking a = pi / 3 and b = pi / 3. So 2pi / 3 = a + b, and you can apply your formula. Another piece of information you need here: cos (pi / 3) has a knowledge value that you can use.

To answer this, we must look at the realm of unity. E-books are physically strong because they look for the right cosine instead of a particularly long answer. In a unit circle cosine proportional to the cost of X, the question is definitely what is the configured pair that corresponds to 2pi / 3? Enter cost X. Hope this helps. In fact, it seemed complicated to me when I wrote it.