NDA 2017 — Mathematics PYQ
NDA | Mathematics | 2017If cot a and cot b are the roots of the equation x2 + bx + c = 0 with b ≠ 0, then the value of cot(a + b) is

If cot a and cot b are the roots of the equation x2 + bx + c = 0 with b ≠ 0, then the value of cot(a + b) is