∣cosx sinxsinx cosx∣=\begin{vmatrix}cosx \ \ sinx\\ sinx \ \ cosx \end{vmatrix} =∣∣cosx sinxsinx cosx∣∣= A0Bcos2xC1Dsin2xAnswer: B. cos2x Read Explanation: ∣cosx sinxsinx cosx∣=\begin{vmatrix}cosx \ \ sinx\\ sinx \ \ cosx \end{vmatrix} =∣∣cosx sinxsinx cosx∣∣==(cosx×cosx)−(sinx×sinx)=(cosx \times cosx)-(sinx \times sinx)=(cosx×cosx)−(sinx×sinx)=cos2x−sin2x=cos2x={cos}^2x- {sin}^2x = cos2x=cos2x−sin2x=cos2x Read more in App
