Polynomial root calculator for iPhone
Enter any polynomial from degree 1 to 20 and get every root — real and complex — instantly, right here in your browser.
Roots and graph appear here once you solve.
What it solves
| Equation type | Example |
|---|---|
| Linear (degree 1) | 3x + 6 = 0 |
| Quadratic (degree 2) | x² − 5x + 6 = 0 |
| Cubic (degree 3) | x³ − 6x² + 11x − 6 = 0 |
| Quartic (degree 4) | x⁴ − 5x² + 4 = 0 |
| Higher degree | up to degree 20 |
Why most calculators stop at quadratics
The quadratic formula gives you an exact answer for degree 2. Degree 3 and 4 have formulas too, but they are long enough that most apps skip them. Above degree 4 there is no general formula at all — the Abel–Ruffini theorem proves one cannot exist — so roots have to be found numerically.
Solve f(x) uses exact symbolic solutions where they exist and numerical methods above that, so you get every root either way, including complex roots that come in conjugate pairs.
How to use it
Enter coefficients directly
Pick the degree, type the coefficients highest power first, and tap Solve. For x² − 5x + 6 you enter 1, −5, 6.
Or type the equation naturally
Switch to freeform entry and write it the way it appears in your textbook, like 3x^4 - 2x^2 + 7x - 1.
Read the graph
Real roots appear marked on the curve where it crosses the x-axis. Pinch to zoom and pan to inspect the shape between roots.
Frequently asked questions
Does it need an internet connection?
No. Every calculation runs on your device, so it works in airplane mode, in an exam room, or anywhere without signal.
What does Solve f(x) Pro unlock?
Degree 4 and higher, complex roots, multiplicity detection, extended precision at 8 or 12 decimal places, and solve history. It is a single one-time purchase, not a subscription.
How do I restore my purchase on a new device?
Open Settings inside the app and tap Restore Purchases.
Can it find complex roots?
Yes, with Pro. Complex roots are shown in a + bi form and always appear in conjugate pairs for polynomials with real coefficients.
What is the difference between a root and a zero?
They are the same thing. A root of the polynomial p(x) is any value of x where p(x) equals zero.
Get in touch
Found a bug or have a feature request? Email mosse692@gmail.com.
Download on the App Store