solve
Solves an equation written as it is on paper, choosing the method itself. One unknown: a linear or quadratic equation is solved exactly, and so is a polynomial of any degree whose roots are rational (a factor that has none is kept as it is, in a solution set). An equation that is not a polynomial is solved numerically when a range (lo, hi) or one starting value follows the unknown. Several equations: a linear system in two or three unknowns, or two equations of any kind from a starting point (x0, y0). Other names in the equation take the values the script has bound, so solve(v = u + a*t, t) uses the script's u, a and v; with quantities (Apas Cloud) each answer has its unit. The unknown may stand alone under a division (1/f = 1/v - 1/u). An expression with no = sign is that expression = 0, and the unknown of a single equation may be left out when it is the only unbound name. One answer is a number, several are a list; "no solution", "no real solution" and "infinitely many solutions" are said in words.
equations(equation[]) -- one to three equations, each written with one = sign (or an expression, meaning = 0)unknowns(name[]) -- what to solve for, one name for each equation, unquotednumbers(number[]) -- optional, for a numerical solution: a range lo, hi or one starting value (one equation); a starting point x0, y0 (two equations)option(string) -- optional "complex": the complex roots of an equation of degree 2 or 3