Precalculus Examples
x3−3x2−2x+6 , x−3
Step 1
Step 1.1
Place the numbers representing the divisor and the dividend into a division-like configuration.
3 | 1 | −3 | −2 | 6 |
Step 1.2
The first number in the dividend (1) is put into the first position of the result area (below the horizontal line).
3 | 1 | −3 | −2 | 6 |
1 |
Step 1.3
Multiply the newest entry in the result (1) by the divisor (3) and place the result of (3) under the next term in the dividend (−3).
3 | 1 | −3 | −2 | 6 |
3 | ||||
1 |
Step 1.4
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
3 | 1 | −3 | −2 | 6 |
3 | ||||
1 | 0 |
Step 1.5
Multiply the newest entry in the result (0) by the divisor (3) and place the result of (0) under the next term in the dividend (−2).
3 | 1 | −3 | −2 | 6 |
3 | 0 | |||
1 | 0 |
Step 1.6
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
3 | 1 | −3 | −2 | 6 |
3 | 0 | |||
1 | 0 | −2 |
Step 1.7
Multiply the newest entry in the result (−2) by the divisor (3) and place the result of (−6) under the next term in the dividend (6).
3 | 1 | −3 | −2 | 6 |
3 | 0 | −6 | ||
1 | 0 | −2 |
Step 1.8
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
3 | 1 | −3 | −2 | 6 |
3 | 0 | −6 | ||
1 | 0 | −2 | 0 |
Step 1.9
All numbers except the last become the coefficients of the quotient polynomial. The last value in the result line is the remainder.
1x2+0x−2
Step 1.10
Simplify the quotient polynomial.
x2−2
x2−2
Step 2
The remainder from dividing x3−3x2−2x+6x−3 is 0, which means that x−3 is a factor for x3−3x2−2x+6.
x−3 is a factor for x3−3x2−2x+6
Step 3
Step 3.1
If a polynomial function has integer coefficients, then every rational zero will have the form pq where p is a factor of the constant and q is a factor of the leading coefficient.
p=±1,±2
q=±1
Step 3.2
Find every combination of ±pq. These are the possible roots of the polynomial function.
±1,±2
±1,±2
Step 4
The final factor is the only factor left over from the synthetic division.
x2−2
Step 5
The factored polynomial is (x−3)(x2−2).
(x−3)(x2−2)