Cube root

[Brock]

I routinely use sqrt(x) for getting a cube root in vb.net. does anyone
know of a way of getting the cube root? I tried cbrt(x) and that
didn't work.
thanks!

[=?Utf-8?B?QU1lcmNlcg==?=]

the cube root of positive x is
x ^ (1 / 3)

"Brock" wrote:

I routinely use sqrt(x) for getting a cube root in vb.net. does anyone
know of a way of getting the cube root? I tried cbrt(x) and that
didn't work.
thanks!

[jch]

Maybe there's built-in VB function to do this but here's how I'd do it.

dblCubeRoot = dblNumber ^ (1/3)

You can change '3' to be whatever root you're trying to get. Ex: (1/2)
would give you the square root.
Brock wrote:

I routinely use sqrt(x) for getting a cube root in vb.net. does anyone
know of a way of getting the cube root? I tried cbrt(x) and that
didn't work.
thanks!

[Andrew Morton]

AMercer wrote:

the cube root of positive x is
x ^ (1 / 3)

Ahem! :-) The /real/ cube root of x is x^(1/3).

Console.WriteLine( -8 ^ (1 / 3)) correctly gives -2. The complex roots are,
of course, beyond my brain this early in the morning.

Andrew

[=?Utf-8?B?QU1lcmNlcg==?=]

Console.WriteLine( -8 ^ (1 / 3)) correctly gives -2.

The minus sign applies to the entire expression; it needs to apply to 8.
(-8) ^ (1 / 3) is NAN.

[Andrew Morton]

AMercer wrote:

>Console.WriteLine( -8 ^ (1 / 3)) correctly gives -2.

The minus sign applies to the entire expression; it needs to apply to
8.
(-8) ^ (1 / 3) is NAN.

<blush>

Andrew