Final answer:
The cotangent of -π/4 is -1.
Step-by-step explanation:
The trigonometric function cotangent (cot) of -π/4 can be found by taking the reciprocal of the tangent function (tan) of -π/4. The tangent function is equal to the ratio of the sine function (sin) and the cosine function (cos).
In this case, the sine of -π/4 is equal to -1/sqrt(2), and the cosine of -π/4 is equal to 1/sqrt(2). Thus, the tangent of -π/4 is equal to -1. Taking the reciprocal, we find that the cotangent of -π/4 is equal to -1.