Evaluate the trigonometric function at the quadrantal angle, or state that the expression is undefined.
cot π
The cotangent function is defined as the reciprocal of the tangent function, so we can find the value of cot π by finding the tangent of π and then taking its reciprocal.
The tangent of π is sin π / cos π. Since sin π is 0 and cos π is -1, we have 0 / -1 = 0.
Therefore, cot π = 1 / tan π = 1 / 0.
Since division by 0 is undefined, the expression cot π is undefined.