Question

prove that sum of the zeroes of quadratic polynomial is equal to -b/a

Answer 1

In a quadratic equation where the coefficient of the first term (x2x2) is unity, following holds:

the sum of the roots is equal to the coefficient of xx with its sign changed;

the product of the roots is equal to the third term.

Your equation is ax2+bx+c=0ax2+bx+c=0coefficient of the first term (x2x2) is NOT 11.

If you write the equation as a(x2+bax+ca)=0a(x2+bax+ca)=0,

the coefficient of the first term of the quadratic expression in the bracket (x2x2) is 11.

Let the roots of the quadratic equation in the bracket be α,βα,β.

Then it can be written as a(x−α)(x−β)=0a(x−α)(x−β)=0,

where α+β=−baα+β=−ba and α.β=ca

Answer 2

Answer in the picture above

binomial formula is also called sridhacharya's formula

Hope it helps you !!!