Hello, im new here but im doing a calculus course online a grade 12 University course and im stuck on how to do first principals derivatives, and since i have no teacher just learning off the book its tough if you guys dont mind help me solve these questions for a practice so i can start to hand in work.

a) f(x)=x²-2x+1

b) f(x)=x³-3x²

c) f(x)=(√2x)

d) f(x)=4/x+1

greatly appreciated