If 2y = ( ^ -1 ( 3 cos x + sin x cos x - 3 sin x ))^ 2 x ∈ (0,...
If 2y=(cot−1(cosx−3sinx3cosx+sinx))2∀x∈(0,2π), then dxdy is equal to
Options
A6π−x
B2x−3π
Cx−6π
D3π−x
Correct answer
C. x−6π
Step-by-step solution
2y=(cot−1cosx−3sinx3cosx+sinx)2 =(cot−1(1−3tanx3+tanx))2 =(cot−1tan(3π+x))2 =(cot−1cot(2π−(3π+x)))2 2y=(6π−x)^{2}, x \in \left(0,\dfrac{\pi}{6}\right) =(π+6π−x)2,x∈(6π,2π) ⇒ \dfrac{2dy}{dx} = 2\left(\dfrac{\pi}{6} - x\right) . \left(-1\right) ⇒ dxdy=x - 6π,x \in \left(0,\dfrac{\pi}{6}\right) \dfrac{dy}{dx} =x−\dfrac{7\pi}{6},x∈(6π,2π) x−6π is matching with one of the given options.