English: Danish Act of Succession Referendum, 2009 — the curve shows minimum combinations of turnout (in percent) and votes in favor (in percent) to pass the law. The shaded area above the curve represents combinations that result in passing the law. For turnout above 80%, a 50% majority of the votes in favor is sufficient to pass the law. Below 40% turnout, even 100% favorable votes are not sufficient to pass the law. Between 40% and 80% turnout, the curve is described by the function ${\displaystyle y={\frac {40}{x}}\times 100\%}$, which can be confirmed using Wolfram Alpha computational engine. The hexagon indicates the actual referendum result.