Question

prove that cos*2thita (1+tan*2thit)=1​

Answer 1

Answer:

cos

2

θ(1+tan

2

θ)=1

Take L.H.S

cos

2

θ(1+tan

2

θ)

cos

2

θ+cos

2

θ.tan

2

θ

cos

2

θ+cos

2

θ.

cos

2

θ

sin

2

θ

cos

2

θ+sin

2

θ

=1

=R.H.S.

Answer 2

Answer:

cos²θ(1+tan²θ)=1

cos²θ×sec²θ=1

cos²θ×1/cos²θ=1

1=1

LHS=RHS

Hence proved