Find the value of

To find: Value of

We have,

Putting π = 180°

= cot (13 × 45°)

= cot (585°)

= cot [90° × 6 + 45°]

= cot 45°

[Clearly, 585° is in III^rd Quadrant and the multiple of 90° is even]

= 1 [∵ cot 45° = 1]