NCERT Exemplar - MCQ
Last updated at March 22, 2023 by Teachoo
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Question 7 Given that sin ΞΈ = π/π, then cos ΞΈ is equal to (A) π/β(π^2 β π^2 ) (B) π/π (C) β(π^2 β π^2 )/π (D) π/β(π^2 β π^2 ) Now, cos2 ΞΈ = 1 β sin2 ΞΈ Putting sin ΞΈ = π/π cos2 ΞΈ = 1β(π/π)^2 cos2 ΞΈ = 1βπ^2/π^2 cos2 ΞΈ = (π^π β π^π)/π^π Taking square root cos ΞΈ = Β± β((π^2 β π^2)/π^2 ) cos ΞΈ = Β± β(π^2 β π^2 )/π Since only positive values are given in options cos ΞΈ = β(π^π β π^π )/π So, the correct answer is (C)
