Exams › JEE Advanced › Maths
Correct answer: (i) 2; (ii) 1/2; (iii) cot(sec⁻¹ 3) = 1/sqrt(8)
Use inverse-function identities. In (i), tan(-pi/3) = -sqrt3 lies in the principal range, so tan⁻¹ returns -pi/3, and sec(-pi/3) = 2. In (ii), cot of cot inverse returns the argument 1/2. In (iii), cos⁻¹(3/4) + sin⁻¹(3/4) = pi/2, so the expression is tan(pi/2 - sec⁻¹ 3) = cot(sec⁻¹ 3) = 1/sqrt(8).