# Rational Zero Problem

• Feb 28th 2009, 12:00 PM
runner940
Rational Zero Problem
Can someone help me solve for this problem. . . I have tried using the reational zero theorom but I think I may have done something wrong because none of the possible zeros work and I can't find a solution. Can someone check to see if this problem has a solution?
(Surprised)
Problem: d^3+5d^2+35d-1825=0
• Feb 28th 2009, 12:14 PM
stapel
Quote:

Originally Posted by runner940
Can someone help me solve for this problem. . . I have tried using the reational zero theorom but I think I may have done something wrong because none of the possible zeros work and I can't find a solution. Can someone check to see if this problem has a solution?
(Surprised)
Problem: d^3+5d^2+35d-1825=0

Being a cubic, this has to have a solution. But it might not be rational.

What did you try? What were your results?

When I checked the graph, it looked like the only real root was between x = 9 and x = 10. At a guess, there may be a typo in the exercise, since they usually intend these things to be neatly solveable. (Surprised)