This is documentation for Mathematica 6, which was
based on an earlier version of the Wolfram Language.

# Root

 Root[f, k]represents the k root of the polynomial equation f[x]0. Root[poly, x, k]gives the k root of the polynomial poly in x.
• f 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.
• For other polynomials, ToRadicals can be used to convert to explicit radicals.
• N finds the approximate numerical value of a Root object.
• Root[f, k] is treated as a numeric quantity if f contains no symbolic parameters.
• Root by default isolates the complex roots of a polynomial using validated numerical methods. SetOptions[Root, ExactRootIsolation->True] will make Root use symbolic methods that are usually much slower.
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