Find the roots (x-intercepts) of polynomial equations.
For ax² + bx + c = 0: x = (−b ± √(b²−4ac)) / 2a.
Discriminant > 0: 2 real roots. = 0: 1 real root. < 0: 2 complex roots.
This tool is most valuable when you need a result to compare against something else: a quoted figure, a competing option, or a budget threshold. Accurate comparisons require accurate inputs and arithmetic — this calculator ensures both.
Many errors with this type of calculation stem from unit inconsistency: mixing metric and imperial, or mixing annual and monthly rates. Ensure all inputs use the same unit system before running the calculation.
A business owner spots that revenue grew from £180,000 last year to £213,400 this year. The calculator confirms the increase is 18.6% — a figure needed for the annual report and for comparing against the industry growth rate cited in the sector report.
Use the quadratic formula: x = (−b ± √(b²−4ac)) / 2a.
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