1.A value of θ∈(0,π3)\theta\in\left(0,\frac{\pi}{3}\right)θ∈(0,3π), for which∣1+cos2θsin2θ4cos6θcos2θ1+sin2θ4cos6θcos2θsin2θ1+4cos6θ∣=0\begin{vmatrix} 1+\cos^{2}\theta & \sin^{2}\theta & 4\cos6\theta \\ \cos^{2}\theta & 1+\sin^{2}\theta & 4\cos6\theta \\ \cos^{2}\theta & \sin^{2}\theta & 1+4\cos6\theta \end{vmatrix}=01+cos2θcos2θcos2θsin2θ1+sin2θsin2θ4cos6θ4cos6θ1+4cos6θ=0is:a.π9\frac{\pi}{9}9πb.π3\frac{\pi}{3}3πc.π6\frac{\pi}{6}6πd.π12\frac{\pi}{12}12πLogin to continueOnly logged in users canattempt or see the solution.
