Question

Prove geometrically Cos(A-B)=CosACosB+ Sin A Sin B
Pls send the solved part​

Answer 1

Answer:

It is a formula of differentiation.

In this we use the formula of identity of,

sin^2+cos^2 = 1

now, take the sin = cos by formula of differentiation.

we also write cos = - sin

But, in this case (A -B) so the negative sing become positive.

(A+B) , so we write this problem cos (A-B) = cosA cosB + sinA sin B

Hope it helps you .....