1.

Consider the following statements:I. 1/(1 + cosθ) + 1/(1 - cosθ) = 2cosec2θII. (1 + tan2θ)/ cosec2θ = tan2θWhich of the following statements are correct.1. Only 12. Only 23. Both 1 and 24. Neither 1 nor 2

Answer» Correct Answer - Option 3 : Both 1 and 2

Given:

Two identities are given

Formula Used:

Basic concept of trigonometric ratio and identities

We know that

(a2 – b2) = (a + b)(a - b)

sin2θ + cos2θ = 1

1 + tan2θ = sec2θ

sinθ = 1/cosecθ

Calculation:

The given identity is 1/(1 + cosθ) + 1/(1 - cosθ) = 2cosec2θ

L.H.S.

Take LCM of denominators

⇒ 2/(1 + cosθ) × (1 - cosθ)

⇒ 2/(1 - cos2θ)

⇒ 2/sin2θ

⇒ 2 cosec2θ = R.H.S.

So, statement 1 is correct

Now, the given identity is (1 + tan2θ)/ cosec2θ = tan2θ

L.H.S.

⇒ (1 + tan2θ)/cosec2θ

⇒ sec2θ/cosec2θ

⇒ sin2θ/cos2θ

⇒ tan2θ = R.H.S.

So, statement 2 is correct

Hence, option (3) is correct



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