A value of x = x1 is said to be the zero of a polynomial
f(x), if we substitute x1 for x in the polynomial f(x), then f(x) vanishes. So if f(x)
is a polynomial, and if f(x1) = 0, then x1 is a zero of the polynomial
f(x).
We know that if x1,x2 and x3 are the zeros of a
polynomial f(x), then the polynomial could be written
as:
f(x) = (x-x1)(x-x2)(x-x3), as putting x= x1 or x= x2
and x=x3 makes th polynomial vanish.
Given are the zeros
: 1-sqrt3, 1+sqrt3 and -2 are the 3 zero.
Then f(x) = {x -
(1-sqr3)}{x-(1+sqrt3)}{x-(-2)}.
f(x) = {x^2
+(-1+sqrt3-1-sqrt3)x + (1-sqrt3)(1+sqrt3)}{x+2}.
f(x) =
{x^2 -2x + [1^2-(sqrt3)^2]}(x+2).
f(x) =
{x^2-2x+1-3}(x+2).
f(x) =
(x^2-2x-2)(x+2).
f(x) = {x^3-2x^2-2x
+2x^2-4x-4}.
f(x) =x^3 -6x -4
.
Therefore x^3-6x-4 is the polynomial with zeros 1-sqrt3 ,
1+sqrt3 , -2.
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