I'd be eternally greatful if someone could help me with these few problems...

1. The Curve C has the equation

y=x²+ax+b

Where a and b are constants.

Given that the minimum point of C has co-ordinates (-2, 5), Find the values of a and b.

2. Given that

dy/dx=2x³+1,

and that y=3 when x=0, find the value of y when x=2.

And finally

3. f(x)=4x-3x²-x³

(a) Fully factorise f(x)=4x-3x²-x³.

I hope someone can help! It needs to be in by tomorrow, and one person has already been thrown off the course as their work was not upto standard. I fear mine will be without this help! Thanks in advance