Question

If `cot^-1(3x + 5)> pi/4`, then find the range of the values of x.

Answer 1

`cot^-1(3x + 5)> pi/4 = cot^-1 1`

⇒ 3x + 5 < 1   ...(As cot⁻¹x is strictly decreasing function in its domain)

⇒ 3x < −4

⇒ `x < -4/3`

`therefore x in (-infty, -4/3)`