If (x 2 – y 2)sinx + (2xy)cosx = x 2 + y 2, then find the value of tan

SOLUTION

If (x² – y²)sinx + (2xy)cosx = x² + y²

Divided both side by x² + y²:

⇒

⇒       ………….(1)

Let ∠C =

Hence (AC)² = (AB)² + (BC)² 

Also (x² + y²)² = (2xy)² + (x² – y²)²

Hence AC = x² + y²

AB = 2xy

BC = x² – y²

Hence ……………………(2)

………………….(3)

⇒

⇒

⇒

⇒

⇒