Polynomial coefficient input
Provide coefficients for a single-variable polynomial from highest to lowest power,
separated by commas. You can mix integers, fractions like 3/4, and
decimals like -0.125 in one line.
x.
Example data table
This example shows how a mixture of fractional and decimal coefficients is converted into integer and primitive integer coefficients for a quartic polynomial.
| Term | Power of variable | Input coefficient | Fraction form | Integer coefficient | Primitive coefficient |
|---|---|---|---|---|---|
| a4 | 4 | 1/2 | 1/2 | 6 | 3 |
| a3 | 3 | -0.75 | -3/4 | -9 | -9 |
| a2 | 2 | 3 | 3/1 | 18 | 9 |
| a1 | 1 | 5/6 | 5/6 | 10 | 5 |
| a0 | 0 | -1/3 | -1/3 | -4 | -2 |
Here the least common multiple of denominators is 12, giving integer coefficients [6, -9, 18, 10, -4]. The greatest common divisor is 2, so the primitive polynomial uses [3, -9, 9, 5, -2].
Formulas used for integer coefficients
Suppose you provide coefficients a_n, a_{n-1}, \ldots, a_0 as integers,
fractions, or decimals. Each coefficient is first converted into a rational
number in lowest terms:
Fraction representation
Every coefficient is written as a_i = p_i / q_i with
integers p_i and positive integers q_i, where
|gcd(p_i, q_i)| = 1.
Common denominator (LCM)
The calculator finds the least common multiple of all denominators:
L = lcm(q_n, q_{n-1}, \ldots, q_0). This is the smallest positive
integer that is divisible by every q_i.
Integer coefficients
Each rational coefficient is scaled to an integer using
b_i = a_i × L = p_i × (L / q_i). Because
L is a multiple of every q_i, the value
b_i is always an integer.
Primitive polynomial
The greatest common divisor of the integer coefficients
b_n, \ldots, b_0 is
G = gcd(|b_n|, \ldots, |b_0|). Dividing each b_i
by G gives a primitive polynomial with integer coefficients
whose gcd is one: c_i = b_i / G.
How to use this calculator
-
Decide the order of your polynomial and list coefficients from
the highest power of
xdown to the constant term. -
Type coefficients into the main input box, separated by commas.
You can mix integers, fractions such as
-7/3, and decimals like2.125. - Choose whether to keep zero terms in the final printed polynomials and whether to display both fraction and decimal representations.
- Press Calculate integer coefficients to run the transformation. The summary panel shows the LCM of denominators, gcd of integer coefficients, and the degree of the polynomial.
- Review the table to see how each original input value becomes a fraction, an integer coefficient, and optionally a primitive coefficient.
- Use the CSV or PDF buttons to download the results and store them with your algebra notes, problem sets, or engineering design calculations.
Example of using this calculator
Suppose you enter the coefficients 1/3, -2, 0.25, 5/6
for a cubic expression. They are interpreted as powers three down
to zero when highest power first ordering is selected.
The calculator converts each value to a simplified fraction and finds the least common multiple of denominators. Those fractions become integer coefficients by multiplying each numerator by the appropriate scaling factor.
You then see the integer polynomial, its primitive version, the overall degree, and a line-by-line table. Finally, you can export the whole transformation to CSV or PDF for later reference.
Why normalize coefficients to integers
Integer coefficients avoid rounding drift in repeated symbolic manipulations. They make factorization easier to inspect by eye, and help match textbook examples that traditionally present polynomials with clean integer parameters instead of fractions or decimals.
Working with ascending coefficient order
When constant term first ordering is selected, the first entry corresponds to power zero, the next to power one, and so on. Trimming leading zeros in this mode removes trailing coefficients that represent the highest zero powers in the expression.
Controlling variable symbols and precision
Advanced controls let you swap the variable symbol from
x to any short label. You can also adjust the decimal
precision used when displaying coefficients so the output matches
your preferred reporting style or institutional formatting guidelines.
Exporting integer coefficients for further work
After verifying the integer and primitive polynomials, you can export the table and summary to CSV or PDF. Those files integrate easily with spreadsheets, laboratory notebooks, or classroom handouts where you document every algebraic transformation step clearly.
Frequently asked questions
Does converting to integer coefficients change the polynomial?
No. Multiplying every coefficient by the same nonzero constant keeps the roots and overall shape identical. The expression looks different, but it represents the same polynomial function on every real or complex input value.
What happens if some coefficients are already integers?
Existing integers are treated as fractions with denominator one. They participate in the least common multiple like other terms. After scaling, those coefficients may increase, decrease, or stay equal depending on the denominators used by neighboring coefficients.
Can I safely mix fractions and decimals together?
Yes. The tool converts decimals into exact rational numbers before computing the least common multiple. That approach avoids early rounding, so the integer coefficients remain mathematically consistent with your original mixed-format inputs from different sources.
Why do some primitive coefficients become negative?
The primitive set results from dividing integer coefficients by their greatest common divisor. If the initial scaled coefficients include negative values, those signs carry through. The greatest common divisor always uses absolute values, so signs are preserved after normalization.
How should I choose between ascending and descending order?
Use descending order when copying standard textbook polynomials that list highest powers first. Ascending order is convenient when coefficients come from recurrence relations or arrays indexed by increasing power of the variable.