NTA Abhyas JEE Main2020MathematicsInverse Trigonometric FunctionsPractice
Consider the following two statements P and Q . P :   cos - 1 ⁡ cos ⁡ 4 π 3 = 4 π 3 Q :   sec 2 ⁡ cot - 1 ⁡ 1 2 + cosec 2 tan - 1 ⁡ 1 3 = 15 Then, which of the following is true?
Options
- ABoth P and Q are true
- BP is true, but Q is false
- CP is false, but Q is true
- DBoth P and Q are false
Correct answer
C. P is false, but Q is true
Step-by-step solution
We have, cos ⁡ 4 π 3 = - cos ⁡ π 3 = - 1 2 Hence, cos - 1 ⁡ - 1 2 = 2 π 3 Therefore, P is false. Now, sec 2 ⁡ cot - 1 ⁡ 1 2 + c o s e c 2 tan - 1 ⁡ 1 3 = 1 + tan 2 ⁡ tan - 1 ⁡ 2 + 1 + cot 2 ⁡ cot - 1 ⁡ 3 = 1 + 4 + 1 + 9 = 15 Therefore, Q is true.