MathematicsMedium66×since 2002Q4078Considering the principal values of the inverse trigonometric functions, the sum of all the solutions of the equation cos−1(x)−2sin−1(x)=cos−1(2x)\cos ^{-1}(x)-2 \sin ^{-1}(x)=\cos ^{-1}(2 x)cos−1(x)−2sin−1(x)=cos−1(2x) is equal to :A0B1C12\frac{1}{2}21D−12-\frac{1}{2}−21Check answerSkip