'A'-level (in old money) or degree level trigonmetry, advanced calculus, vector analysis or other, more estoric, branches of mathematics are not essential for an aspirant pilot.
However, basic trigonometry is needed for an understanding of the resolution of forces when studying basic principles of flight, for example.
Presumably, Jerry Lee, you do know what a 'square root' is? But you shouldn't need to be able to calculate one these days, a dark art from before even my time - although I was taught how.