Originally Posted by
Jen1603 Use the remainder theorem to factorise :
1)
The rational roots theorem tells us if this has rational roots, they will be
Test each one using the remainder theorem to see which one(s) satisfy
I found , so is a factor.
To find the remaining factors, you could test the rest of the possible rational roots using the remainder theorem or use synthetic division with divisor -2to reduce the polynomal to a quadratic that you can factor.
Code:
-2 | 1 3 0 -4
-2 -2 4
------------
1 1 -2 0
The quadratic remaining after factoring is
That factors into
Originally Posted by
Jen1603 2)
Test these factors
There are no sign changes in this polynomial, so no need to check for positive zero because there aren't any (Descartes Rule of Signs)