Question

    If θ is an acute angle and sin θ + cosec θ = 2, then the value of sin2 θ + cosec2 θ is:

    A 1 Correct Answer Incorrect Answer
    B 2 Correct Answer Incorrect Answer
    C 5 Correct Answer Incorrect Answer
    D 4 Correct Answer Incorrect Answer

    Solution

    Given – sin + cseccθ = 2, let x = sin θ, then cosec θ =1/x ATQ- x+1/x =2   x²+1 = 2x x²-2x+1 0 (x-1)2 = 0 x-1 =0 x =1. Thus, sin θ = 1, which means θ = 90°. Now, Sin 2 θ = 15=1 Similarly, Cosec2 θ = 1 Therefore, Sin 2 θ + Cosec2 θ =1+1=2 So, the value is 2.

    Practice Next