Hello everyone!

Here is the problem, I would appreciate some help

**Exercise 2.1.3**

Find the average rate of change of the function h(t) = cot(t) over the interval

π/6 -> π/2

I don't have cot on my calculator, so before, when I solved exercises like this one I would first calculate 1/tan. The problem is, tan is undefined for π/2. So, any ideas on what I should do?

By the way, is there some easy way to write equations, fractions etc. more neatly on MHF? I really love this forum and would like to be able to ask for help in more neat ways, so it does not become so difficult for everyone to read it.