Quadratic Inequality Solver
Quadratic Inequality Solver with explicit inputs, formulas and domain checks.
Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Returns interval notation for the real solution set, rather than a rendered graph. Real-number solutions; parentheses exclude endpoints, square brackets include them. Coefficients use floating-point arithmetic, so nearly repeated roots may be sensitive to rounding.
Example Calculation
- a: 1
- b: -3
- c: 2
- Relation: <
x²−3x+2<0 holds between its roots1 and2.
Frequently asked questions
How do I use this calculator?
Enter a, b, c, relation. The result updates automatically. Use Reset to restore the example values.
What method does it use?
Solve ax²+bx+c relation 0 using real roots and the sign of a.. Returns interval notation for the real solution set, rather than a rendered graph. Real-number solutions; parentheses exclude endpoints, square brackets include them. Coefficients use floating-point arithmetic, so nearly repeated roots may be sensitive to rounding.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.