Math Help - the chain rule

I have 2 questions

1) y=sin(x^2) = 2X cos(x^2)

which i sort of understand but not shure how to do

2) y= (sinx)^2 cn someone explain the answer ?

It's like when differentiating in this case our is hence, we require to apply the chain rule (actually, when one differentiates is applyin' the chain rule, it's just that ), hence