Sum and Product of Roots

Hi everyone! So, today we learned about Sum and Product of Roots.

The Quadratic equation ax²+bx+c=0 has roots:

and

therefore;

Sum of roots

;

Product of roots

; and

In general form, x² - ( sum of roots) x + ( product of roots) = 0

For example:

1. Find the sum and product of the roots of the equation: x² - 5x + 10

Identify the coefficients:

a = 1

b = -5

c = 10

Now use the formula and substitute the values:

Sum of roots

( - b / a ) = - ( -5 / 1 ) = 5

Product of roots

( c / a ) = ( 10 / 1 ) = 10

For today's notes:

http://pc30swinter2011.pbworks.com/f/Sum+and+Product+of+Roots.pdf