Concept:Use principal values of inverse trigonometric functions and simplify the expression.Explanation:Evaluate each term using standard principal values.tan−1(−3)=−3πsin−1(21)=4πcos−1(−21)=π−cos−1(21)=π−3π=32πNow substitute these values into the given expression.−3π−4π+32πCombine the terms involving π/3.(−3π+32π)−4π=3π−4πTake LCM of 3 and 4, which is 12.124π−3π=12πAnswer:The value is 12π, which matches option C.