# Thread: Finding the roots?

1. ## Finding the roots?

if r and s are roots of the equation 3x^2 - 7x +1 =0 compute r^3 s + rs^3.

How do i know which is r and which is s?
thanks!!!

2. ## Re: Finding the roots?

Originally Posted by mmathh
find the roots of 3x^2 - 7x +1 =0
thanks!!!
use the quadratic formula

3. ## Re: Finding the roots?

Originally Posted by mmathh
How do i know which is r and which is s?
Notice that in the equation you gave, $r^3s+rs^3$, it doesn't matter which of the two roots you assign to s or r, the answer you will get at the end will be the same, so you can set r and s however you want to.

4. ## Re: Finding the roots?

heh heh yeah i totally noticed that right after i posted it...thanks! i feel dumb. hehe