FORMULA

FORMULA, in Mathematics, a theorem or general rule or expression, for solving certain particular cases of some problem; so $\backslash frac\{1\}\{2\}s\; +\; \backslash frac\{1\}\{2\}d$ is a general formula for the greater of two quantities whose sum is $s$, and difference $d$; and

$\backslash frac\{1\}\{2\}s\; -\; \backslash frac\{1\}\{2\}d$ is the formula or general value for the less quantity. Also $\backslash sqrt\{ax-x^2\}$ is the formula or general value of the ordinate to a circle whose diameter is $a$ and abscissa $x$.