Solves a cubic equation,
a0 x³
+ a1 x² + a2 x
+ a3 = 0, analytically, for real coefficients. The
coefficients will, however, be called a, b, c, and d,
respectively. It must, of course, be a ≠ 0.
(For the method, see below, [Tuma].)
Supplementarily ("new problem"), the coefficients
are computed from given roots. The roots of a cubic are: one, always real;
the other two, real or complex conjugate. So, giving "Complex", 3 4 5
means 3, 4+5i and 4−5i.
A plot of the cubic is shown for x between the given
extremes. |
• Method, in J. Tuma (Tuma, Jan J. and
Ronald A. Walsh,
"Engineering Mathematics Handbook").
• Wikipedia: Cubic equation
(old page)
• 1777-04-30: Gauss, Johann Carl Friedrich
(1855-02-23) |
