Method on @infsup: nthroot (X, N)

Compute the real n-th root of X.

Accuracy: The result is a valid enclosure. The result is a tight enclosure for n ≥ -2. The result also is a tight enclosure if the reciprocal of n can be computed exactly in double-precision.

See also: @infsup/pown, @infsup/pownrev, @infsup/realsqrt, @infsup/cbrt.

Package: interval