integration and differenciation

hello! I had my class test today, but there are 2 questions on which I am doubtful of my answer, could you please check?

1) integral from -1 to x of (3t^4 + 15 t^2)e^(t^2)

a) is never null

b) has a point of local minimum at -1

c) is decreasing

d) none of the preceiding

I said b

2) the mean value of 2xsin(x^2) in (0; root of pi) (the boundaries are included but I don't know how to write that brachets) is

a) 2

b)1/root of pi

c) 0

d) none of the preceding

I said d

Thank you so much!