The linear question y=-2x+4 is represented on the graph below (2,0)
(0,4)
(0,-1)
(4,-4)

The question is obviously incomplete, but if the polynomial has all real coefficients, then Patricia is partially right in that the polynomial has at least degree 4. Complex roots occur in conjugate pairs, so if 3+4i is a root, then so is 3-4i. So we know at a minimum that we can write

where is some real number.