Find the zeroes of the following quadratic polynomials and verify the relationship between the zeroes and the coefficients
Question:
Find the zeroes of the following quadratic polynomials and verify the relationship between the zeroes and the coefficients
$x^{2}-2 x-8$
Solution:
$x^{2}-2 x-8=0$
$\Rightarrow x^{2}-4 x+2 x-8=0$
$\Rightarrow x(x-4)+2(x-4)=0$
$\Rightarrow(x-4)(x+2)=0$
$\Rightarrow(x-4)=0$ or $(x+2)=0$
$\Rightarrow x=4$ or $x=-2$
Sum of zeroes $=4+(-2)=2=\frac{2}{1}=\frac{-(\text { coefficient of } x)}{\text { coefficient of } x^{2}}$
Product of zeroes $=4(-2)=-8=\frac{-8}{1}=\frac{\text { constant term }}{\text { coefficient of } x^{2}}$