• Root[f, k] represents the k root of the polynomial equation f[x] 0.
must be a Function
object such as (#^5 - 2 # + 1)&
• Root[f, k] is automatically reduced so that f has the smallest possible degree and smallest integer coefficients.
• The ordering used by Root takes real roots to come before complex ones, and takes complex conjugate pairs of roots to be adjacent.
• The coefficients in the polynomial f[x] can involve symbolic parameters.
• For linear and quadratic polynomials f[x], Root[f, k] is automatically reduced to explicit rational or radical form.
finds the approximate numerical value of a Root
• Operations such as Abs
can be used on Root
• Root[f, k] is treated as a numeric quantity if f contains no symbolic parameters.
• Root by default isolates the roots of a polynomial using approximate numerical methods. No cases are known where this approach fails. SetOptions[Root, ExactRootIsolation->True] will however make Root use much slower but fully rigorous methods.
• New in Version 3.