Add relevent links to other math functions [CNT-671]

[aliphys]

[CLAassistant]

All committers have signed the CLA.

[aliphys]

@per1234 could you review this?

[per1234]

It is somewhat a duplicate of https://github.com/arduino/reference-en/pull/816

The problem is that we used to have a very nice system that generated these links automatically. That system was broken and I have never been able to get a straight answer on whether it can simply be fixed rather than requiring us to manually replace and maintain a huge number of links just to get back to what we had for years.

[aliphys]

@per1234 If this PR is obsolete, could you close it? Thanks!

[per1234]

@aliphys since I still have not been able to get a straight answer after two years of trying, I think we must conclude that the automated links system will never be repaired and that it will be necessary to manually replace and maintain the links.

So this PR is not obsolete.