Question

How do you evaluate the expression `cot 180`?

Answer 1

...see explanation

Explanation:

I will assume we are working in degrees, not radians.

Remember that `cot theta` = `1/tan theta` = `cos theta/sin theta`

...and note that the sine of a 180 degree angle is zero, and the cosine of that angle is -1. So, this evaluates to a division by zero. Therefore, `cot 180` is undefined.