How do I solve : COT pi/4 ... ?

Cot x = cos x / sin x

cot π/4 = cot 45° = cos 45° / sin 45°

We know that sin 45° and sin 45° have the same value:

cos 45° = sin 45° = √2 / 2;

cos 45° / sin 45° = √2/2 : √2/2 = 1

Answer:

cot π/4 = 1