| Polynomials (Math) | Close X |
Consider a quadratic polynomial p(x) = 3x2– 5x – 12.
Can we find out the sum and the product of the zeroes of this polynomial?
Yes, we can find the sum and the product of zeroes but firstly we have to find out the zeroes of the polynomial.
Here, the zeroes of polynomial p(x) are 3 and
.
Now, the sum of zeroes = 3 +![]()
And the product of zeroes = 3 ×
= – 4
Can we find out the sum and the product of zeroes by any other method?
Yes, there is also a method in which there is no need to find out the zeroes. In that method we use the coefficients of the polynomial to find the sum and the product of zeroes.
Firstly let us see the relation between the sum and product of zeroes and the coefficients of the polynomial.
Let us first consider a quadratic polynomial p(x) = ax2 + bx + c, where a, b and c are constants.
If αand β are the zeroes of p(x) = ax2 + bx + c, then,
|
Sum of zeroes = Product of zeroes = αβ = |
Now, let us find the sum and product of zeroes of the polynomial given in the beginning, using these relations.
The polynomial is p(x) = 3x2 – 5x – 12.
On comparing this equation with ax