# Finding the roots?

• Nov 20th 2011, 02:41 PM
mmathh
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!!!
• Nov 20th 2011, 02:42 PM
skeeter
Re: Finding the roots?
Quote:

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

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.