Question

Verify the identity.

cos (x + pi/2) = -sin x

Answer 1

@gorv

Answer 2

pi/2=90 degree

Answer 3

now if we add something it will go in second quaderent

Answer 4

in second quad cos give negative value

Answer 5

cos(pi/2+x)=-sinx

Answer 6

\[\cos \left( A+B \right)=\cos A \cos B-\sin A \sin B\]
\[\cos \frac{ \pi }{ 2 }=0,\sin \frac{ \pi }{ 2 }=1\]

Answer 7

or u can use formula
cos(a+b)

Answer 8

so I'm having trouble figuring out where to plug things into but i'll try
cos A + B = cos pi/2 cos 0 - sin pi/2 sin 1
I don't think any of that was right @gorv