Root Tool

Calculate indexed roots of real numbers or solve polynomial equations from degree two to six. Explore real and complex solutions, choose decimal precision, inspect a zoomable function graph, review numerical details, and export results.

For an even index, negative numbers have no real roots. Select complex roots to see every solution.
Solutions
Calculation details
Interactive graph
5×
Hover or tap the curve to inspect coordinates. Adjust the slider to change the view.

Table of Contents

  1. How Root Tool Works?
  2. Practical Use Cases
  3. Accuracy and Limitations
  4. Frequently Asked Questions (FAQs)
  5. Cite This tool

Highlights

  • Indexed roots from 1st to 100th degree
  • Real and complete complex-root options
  • Polynomial roots for degrees 2 to 6
  • Interactive zoomable graph with coordinate inspection
  • CSV, JSON, TXT and SVG exports

How Root Tool Works?

An indexed root solves an equation of the form xn = a, where a is the entered number and n is a whole-number index from 1 to 100. For a positive number and even index, there are two real solutions, one positive and one negative. An odd index gives one real solution for any real number. A negative number with an even index has no real solution.

xn=a

Choosing all complex roots finds solutions around a circle in the complex plane. For non-zero a, their angles are evenly separated; when a is zero, the tool displays zero once.

zk=|a|1n(cos⁡θk+isin⁡θk),θk=arg(a)+2πkn

The polynomial mode accepts real coefficients for degrees 2 through 6, entered from the highest power to the constant term. It finds all roots, including complex roots, by Durand–Kerner iteration followed by Newton refinement. The leading coefficient must be non-zero.

anxn+⋯+a1x+a0=0

Input or optionEffect
Number and root indexSolve xn = a.
Real or all complex rootsRestrict to real solutions or include complex ones.
Polynomial degree and coefficientsSolve a degree 2–6 polynomial, including complex solutions.
Decimal placesDisplay 2, 4, 6, 8, 10 or 12 decimal places.
Graph view spanZoom the real-valued function plot; hover or tap to inspect coordinates.

Results include a root table, magnitudes for indexed roots or residuals for polynomial roots, and an interactive graph of y = xn − a or y = f(x). Results can be exported as CSV, JSON, TXT or graph SVG.

Practical Use Cases

Students: Compare square, cube and higher-order roots, including why negative inputs behave differently with odd and even indices. Use the function graph to identify real x-intercepts.

Algebra teachers: Demonstrate the difference between real and complex solutions and explore how polynomial coefficients change root locations.

Engineering students: Analyse quadratic through sextic characteristic equations, review complex root pairs and inspect the numerical residual at each computed solution.

Researchers and technical writers: Check small polynomial examples, control displayed decimal places and export root lists as CSV, JSON or TXT for documentation.

Visual learners: Adjust the graph's viewing span and hover or tap the curve to see how the function changes near a root.

Accuracy and Limitations

Calculations use JavaScript floating-point arithmetic, so displayed digits beyond numerical precision are not guaranteed. Indexed roots support integer indices from 1 to 100; even roots of negative numbers require the complex option. Polynomial solving supports real coefficients and degrees 2–6 only, with a non-zero leading coefficient and coefficient magnitudes no greater than 1080. The iterative solver may fail for ill-conditioned or tightly clustered roots; it rejects solutions with excessive residuals. Repeated roots can be numerically sensitive. The graph shows real x-values only, so non-real roots are listed but not plotted as points. Decimal-place settings change presentation rather than internal precision.

Frequently Asked Questions

A square root is a number whose square equals the original number. A cube root is a number whose cube equals it.

No. Every even power of a real number is non-negative, so a negative radicand has only non-real complex even roots.

For polynomials with real coefficients, the complex conjugate of any non-real root must also be a root.

Exactly six when counted with multiplicity, according to the fundamental theorem of algebra.

A repeated root satisfies the polynomial more than once in its factorisation, such as x = 2 in (x − 2)².

Cite This tool