Write the expression as the sine, cosine, or tangent of an angle.

cos 112° cos 45° + sin 112° sin 45°

I know the formulas, but I'm confused on whether you subtract or divide. Don't you do the opposite?

Question

Write the expression as the sine, cosine, or tangent of an angle.

cos 112° cos 45° + sin 112° sin 45° 

I know the formulas, but I'm confused on whether you subtract or divide. Don't you do the opposite?

anonymous · Answer

If there's a + in the middle, don't I subtract? Would I get cos(67)?

dumbcow · Answer

subtract

= cos(112 -45)

anonymous · Answer

I thought so. Thanks! God bless!

dumbcow · Answer

your welcome

cosine you do opposite
sine its straightforward

anonymous · Answer

Oh, wait. So that means this one-->sin 9x cos x - cos 9x sin x I should get sin(10x)? Right?

anonymous · Answer

Nope, I just got that one wrong. Poop.

dumbcow · Answer

no since there is "-" in between you subtract the angles
its the sine formula

anonymous · Answer

Yup, now I know. Thank you! God bless!