Question

Evaluate cot(tan⁻¹(2x) + cot⁻¹(2x))

Answer 1

cot(tan⁻¹(2x) + cot⁻¹(2x)) = `cot (pi/2)`

= 0      .......`[∵ tan^-1x + cot^-1 x = pi/2]`