How would you solve this?
(cos a- cosb)^2 +(sina-sinb)^2 = (cos(a-b)-1)^2+ (sin(a-b)-0)^2

Question

How would you solve this? 
(cos a- cosb)^2 +(sina-sinb)^2 = (cos(a-b)-1)^2+ (sin(a-b)-0)^2

solomonzelman · Answer

By expanding everything.

You might need these identities.

in(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

solomonzelman · Answer

$$Cos^2x+Sin^2x=1$$$$(a-b)^2=a^2-2ab+b^2$$

solomonzelman · Answer

Theese 6 is all what you need to know I think. You should be able to do this, (sorry)

anonymous · Answer

thankyou

solomonzelman · Answer

I didn't help you much, this is too much work...

anonymous · Answer

it's fine ty anyways

solomonzelman · Answer

Alright, then yw.

solomonzelman · Answer

ty for the medal... guess best would be trying to do it, I'll be guiding if you need more assistance.