Question

if tan (x + y) tan (x - y) = 1 , then find tan x.​

Answer 1

Answer:

tan(x+y)+tan(x−y)=1

Differentiating w.r.t. x, we get,

sec

2

(x+y)[1+

dx

dy

]+sec

2

(x−y)[1−

dx

dy

]=0

dx

dy

[sec

2

(x+y)−sec

2

(x−y)]=−[sec

2

(x+y)+sec

2

(x−y)]

dx

dy

=

sec

2

(x−y)−sec

2

(x+y)

sec

2

(x+y)+sec

2

(x−y)