Find the roots of the polynomial equation.
; 2,3
Since you are given that 2 is a root, we
do this synthetic division
2 | 1 -5 11 -25 30
| 2 -6 10 -30
---------------------
1 -3 5 -15 0
So now we have factored the original polynomial as
Now we factor the cubic polynomial in
the 2nd parentheses, using the fact that 3 is
a root of the original, so it must be a
root of the cubic polynomial in the 2nd
parentheses:
3 | 1 -3 5 -15
| 3 0 15
---------------
1 0 5 0
So now we have factored the original polynomial as
or
Setting the first two parentheses = 0 gives
the given two roots, 2 and 3. To find the
other roots, we set the third factor = 0
Add -5 to both sides
Take the square roots of both sides:
So the roots are 2, 3,
, and
Edwin