## Math4Life Group Title Use a half–angle identity to find the exact value of sin 105° one year ago one year ago

1. ParthKohli Group Title

$\sin(90 + 15) = \sin(90)\cos(15)+\sin(15)\cos(90)$The second term would cancel.

2. ParthKohli Group Title

I would use the half-angle identity to find $$\sin(15)$$.

3. Math4Life Group Title

I'm confused, we haven't learned this yet, i'm doing extra credit where we do a practice on the next thing we learn that we haven't been taught yet to see how we do can you explain?

4. ParthKohli Group Title

Do you know what the half angle identity says?

5. Math4Life Group Title

what does it say?

6. ParthKohli Group Title

Sorry, was afk. I think it is a lot of typing so here: http://www.mathwords.com/h/half_angle_identities.htm

7. Math4Life Group Title

Trig identities that show how to find the sine, cosine, or tangent of half a given angle.

8. Math4Life Group Title

@ParthKohli You there? What's next?

9. ParthKohli Group Title

Use those to find $$\sin(15)$$ from $$\sin(30)$$.