Question

if tan (x+y) =p and tan (x-y)=q then value of tan 2y is​

Answer 1

Step-by-step explanation:

tan 2y = tan{(x+y) + (x - y)}

= {tan(x+y) + tan(x-y)}/{1 - tan(x+y).tan(x - y)}

= (x + y)/(1 - xy).

Similarly tan 2y = tan {(x+y) - (x-y)}

= {tan(x+y) - tan(x-y)}/{1 + tan(x+y).tan(x-y)}

= (x-y)/(1+xy)