Question

Write the equation of a polynomial of degree 3, with zeros 1, 2 and -1 where f(0)=2

Answer 1

f(x) = x^3 - 2x^2 - x + 2

Explanation:

since the zeroes are 1,-1, and 2. we can write the function like

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

f(x) = (x^2-1)(x-2)

f(x) = x^3 -2x^2 -x +2

and it is true that f(0)=2