Question

verify the identity:
sin(π/2+x)=cosx

Answer 1

sin ( pi/2 + x ) = sin(pi/2)cos(x) + cos(pi/2)sin(x) = 1*cos(x) + 0

Answer 2

how did you get to that point?

Answer 3

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

Answer 4

Addition identities. They're pretty great.

Answer 5

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

Answer 6

oh yes, i remember those formulas! thanks for the refresher ;)

Answer 7

np, I don't remember them I google them:)

Answer 8

well ok sin(a+b) I remembered..

Answer 9

hahaha @zzr0ck3r ok, thanks anyways

Answer 10

\[\sin{\pi\over2}\cos x+\cos{\pi\over2}\sin x\]\[(1)(\cos x)+0(\sin x)\]\[\cos x+0\]\[\sin({\pi\over2}+x)=\cos x\]

Answer 11

np

Answer 12

that's pretty:)

Answer 13

what is? lol

Answer 14

i have no idea..maybe your beautiful math response...its neatly typed haha

Answer 15

lol, hope i've been helpful! :)

Answer 16

yes, thanks! @yummydum

Answer 17

Anytime! :)