How do you use the rational root theorem to find the roots of #x^3-9x^2+14x=48#?
1 Answer
Test all possible values of
Any that satisfy the equation are roots of the equation.
Explanation:
The candidates for rational roots of
(notice, I've slightly re-arranged the equation)
are
Therefore there are
(It is useful if you can set this up as a spreadsheet or computer program.)
Here are the evaluations (using synthetic substitution/division) for the first
This gives us
Not of the subsequent factors gave a result of
It might be noted that treating these entries as synthetic division gives:
and taking the discriminant of