Differentiate (cos θ - sin θ)\(^2\)
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Correct Answer: Option A
Explanation:
y = (cosθ - sinθ)
dy/dx = 2(cosθ - sinθ)(-sinθ - cosθ)
dy/dx = 2(-cosθsinθ - cos2θ + sin2θ)
dy/dx = 2(- cos\(^2\)θ + sin\(^2\)θ)
= -2(cos\(^2\)θ - sin\(^2\)θ)
= -2(1 - 2sin\(^2\)θ)
= -2cos2θ
y = (cosθ - sinθ)
dy/dx = 2(cosθ - sinθ)(-sinθ - cosθ)
dy/dx = 2(-cosθsinθ - cos2θ + sin2θ)
dy/dx = 2(- cos\(^2\)θ + sin\(^2\)θ)
= -2(cos\(^2\)θ - sin\(^2\)θ)
= -2(1 - 2sin\(^2\)θ)
= -2cos2θ