Question

To find the zeroes of a quadratic polynomial , should we split the middle term or should we use the identity (x+a)(x+b)=x^{​​​​​​2}​​​+(a+b)x+ab?

Answer 1

To find zeroes of a polynomial. it is convinient to use splitting middle term method.
For splitting middle term we use that identity.
we convert
x^2+(a+b)x+ab into
(x-a)(x-b)
here a and b are the zeroes of the polynomial.


so this two are connected.