Expert: Ahmed Salami - 1/8/2009

Question
what are the roots of x^3-4x^2+x-6 I've tried 1,-1,2,-2,and other number I've used are too large so please help me solve this equation.

Answer
Hi LeMario,
I figure you've been trying to take advantage of the remainder theorem. Well, this equation happens to be one that doesnt have an integral solution because none of the factors of -6 satisfies it. So what do we do?
Depending on what you're studying exactly, there are a number of advanced methods to solve a cubic equation. From my own experience, i see this equation and know that it has only one real root, which is positive, the remaining two roots being complex.
If you're just interested in finding the roots in whatever way, you could use the Newton Method which requires iterations. I guess you're doing pre-calculus so i think that one is a bit early. Anyway, just for the sake of a solution, the real root is about 4.112
You can always get back to me.

Regards