Question
If θ is an acute angle and sin θ + cosec θ = 2, then
the value of sin2 θ + cosec2 θ is: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.
A-5,  A,  35,  52, 78, 115
30, 42, 48, 54, 65, 81, 126
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