write the polynomial function of least degree that has real coefficeents the given zeros, and a leasing coefficiennt of 1. 1,-3,4
Since the leading coefficient is 1, just multiply the factors for all the roots:
f(x) = (x-1)(x+3)(x-4)
If the leading coefficient had not been 1, then you'd just have tacked that on the front as a multiplying factor.