Question

If tan’ 0 - 2 tan’ • + 1, then the value of cos 20 + sin? o is

Answer 1

Answer:

Correct option is

B

0

given tan

2

θ=2tan

2

ϕ+1

⇒1+tan

2

θ=2(1+tan

2

ϕ)⟶(1)

now, cos2θ+sin

2

ϕ=

1+tan

2

θ

1−tan

2

θ

+1−

1+tan

2

ϕ

1

=

1+tan

2

θ

1−tan

2

θ

+1−

1+tan

2

θ

2

, using equation (1)

=0

Hence, option 'B' is correct