Question

How do you write the polynomial function with leading coefficient 2, Degree : 3, Zeros : -2, 1, 4?

Answer 1

`f(x)=2(x+2)(x-1)(x-4)`

`=2(x^3-3x^2-6x+8)`

`=2x^3-6x^2-12x+16`

Explanation:

Zeroes correspond to factors. If a cubic has zeroes `r_1`, `r_2` and `r_3` and leading coefficient `a`, then it is equal to

`a(x-r_1)(x-r_2)(x-r_3)`