Solution :
The value of Cot 0 degrees is equal to ∞ or not defined.
Proof :
∠ A is made smaller and smaller in the right Δ ABC till it becomes zero. As ∠ A gets smaller and smaller the length of the side BC decreases. The point C gets closer to the point B and finally when ∠ A becomes very close to 0 degrees, AC becomes almost the same as AB, and BC gets very close to 0.
By using trigonometric formula,
Cot A = baseperpendicular = bp
Cot A = ABBC = AB0 = 10, which is not defined.
Hence, cot0∘ = ∞ or not defined.