csqrtf3
Complex square root functions
Part of csqrt(3).
Usage
double complex
float complex
long double
complex
Library
Math Library (libm, -lm)
Overview
The csqrt(), csqrtf(), and csqrtl() functions compute the square root of z in the complex plane, with a branch cut along the negative real axis. In other words, csqrt(), csqrtf(), and csqrtl() always return the square root whose real part is non-negative.
Return values
These functions return the requested square root. The square root of 0 is +0 0, where the imaginary parts of the input and respective result have the same sign. For infinities and s, the following rules apply, with the earlier rules having precedence:
Input Result k + *I + *I (for all k) - + *I *I
+ *I + *I k + *I + *I
+ k*I + *I - + k*I +0 + *I
+ k*I + 0*I
For numbers with negative imaginary parts, the above special cases apply given the identity:
csqrt(conj(z)) = conj(csqrt(z))
Note that the sign of is indeterminate. Also, if the real or imaginary part of the input is finite and an is generated, an invalid exception will be thrown.
History
- FreeBSD 16.0-CURRENT (2026-10-27) to FreeBSD 13.3-RELEASE: the text shown here
- FreeBSD 13.2-RELEASE to FreeBSD 13.0-RELEASE
- FreeBSD 12.4-RELEASE
- FreeBSD 12.3-RELEASE
- FreeBSD 12.2-RELEASE
- FreeBSD 12.1-RELEASE
- FreeBSD 12.0-RELEASE
- FreeBSD 11.4-RELEASE
- FreeBSD 11.3-RELEASE
- FreeBSD 11.2-RELEASE
- FreeBSD 11.1-RELEASE
- FreeBSD 11.0-RELEASE
- FreeBSD 10.4-RELEASE
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- FreeBSD 10.2-RELEASE
- FreeBSD 10.1-RELEASE
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- FreeBSD 8.4-RELEASE
- FreeBSD 8.3-RELEASE
- FreeBSD 8.2-RELEASE
- FreeBSD 8.1-RELEASE
- FreeBSD 8.0-RELEASE