0.75+-0.25 use algorithms to find this answer

What is the exact volume of the cylinder? 16in going into the middle of the top of the cylinder and 40in in height a) 25,600(pi)3 b)10,240(pi)3 c)1280(pi)3 d)640(pi)3

What is the y-intercept of the line given by the equation

Is this a polynomial function? i need to know asap