Question

Cos A minus b by Cos A into Sin B that is equal to tan A + cot b​

Answer 1

GIVEN  :  COS(A-B ) / ( COS A SIN B ) ................eq 1

using the below identity in eq 1 :

COS(A-B ) = COS A COS B + SIN A SIN B

=  $\frac{cos A cos B + sin A sin B }{cos A sin B}$

= $\frac{cos A cos B}{cos A sin B }$ + $\frac{sin A sin B}{cos A sin B}$

= cot B + tan A

hence proved