1. Rational Roots Theorem
(really this time)
At the Feet of an Ancient Master
by flickr user premasagar
2.
3.
4. Determine each value of k.
(a) When x 3 + kx2 + 2x - 3 is divided by x + 2, the remainder is 1.
5. Determine each value of k.
(a) When x 3 + kx2 + 2x - 3 is divided by x + 2, the remainder is 1.
6. Determine each value of k.
(b) When x4 - kx 3 + 2x2 + x + 4 is divided by x - 3, the remainder is 16.
7. When the polynomial 2x 2 + bx - 5 is divided by x - 3, the remainder is 7.
(a) Determine the value of b.
(b) What is the remainder when the polynomial is divided by x - 2?
8. Rational Roots Theorem
For any polynomial function
if P(x) has rational roots, they may be found using this procedure:
Example
Procedure
Step 1: Find all possible ƒ(x) = 3x3 - 4x2 - 5x + 2
numerators by listing the
positive and negative
1, -1, 2, -2
factors of the constant
term.
9. Rational Roots Theorem
For any polynomial function
if P(x) has rational roots, they may be found using this procedure:
Example
Procedure
ƒ(x) = 3x3 - 4x2 - 5x + 2
Step 2: Find all possible
denominators by listing
the positive factors of the 1, 3
leading coefficient.
10. Rational Roots Theorem
For any polynomial function
if P(x) has rational roots, they may be found using this procedure:
Example
Procedure
ƒ(x) = 3x3 - 4x2 - 5x + 2
Step 3: List all possible
rational roots. Eliminate
1, -1, 2, -2
all duplicates.
1, 3
11. Rational Roots Theorem
For any polynomial function
if P(x) has rational roots, they may be found using this procedure:
Example
Procedure
ƒ(x) = 3x3 - 4x2 - 5x + 2
Step 4: Use synthetic division and
the factor theorem to reduce ƒ(x)
to a quadratic. (In our example,
we’ll only need one such root.)
is a root!
-1
So,
12. Rational Roots Theorem
For any polynomial function
if P(x) has rational roots, they may be found using this procedure:
Example
Procedure
Step 5: Factor the quadratic.
Step 6: Find all roots.