I would say that the really complicated maths I studied at university doesn’t get used very much at all, however some of the simpler stuff I learned at school does. In fact today was a good example where I had to resolve a force into two directions, this was a simple problem involving one right angled triangle, however I realised I had to think really hard about how to do it correctly. While I was at university and school I would have done problems like this every day, however now I am out of practice. It made me happy though that I could eventually remember what I needed to do, so the knowledge is in there, just buried very deep.
It is easy to get lazy when it comes to maths, because a lot of engineering now involves computers that can work out complex calculations very quickly – but often it helps to understand how the computer has come to a solution, even if you can’t completely follow the complex mathematics that it used.