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C99 Section 7.12.1 defines two types of errors that relate specifically to math functions  in {{math.h}} \[[ISO/IEC 9899:1999|AA. References#ISOBibliography#ISO/IEC 9899-1999]\]:

a domain error occurs if an input argument is outside the domain over which the mathematical function is defined.

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The exact treatment of error conditions from math functions is quite complicated.  C99 Section 7.12.1 defines the following behavior for floating point overflow \[[ISO/IEC 9899:1999|AA. References#ISOBibliography#ISO/IEC 9899-1999]\]

A floating result overflows if the magnitude of the mathematical result is finite but so large that the mathematical result cannot be represented without extraordinary roundoff error in an object of the specified type. If a floating result overflows and default rounding is in effect, or if the mathematical result is an exact infinity from finite arguments (for example log(0.0)), then the function returns the value of the macro HUGE_VAL, HUGE_VALF, or HUGE_VALL according to the return type, with the same sign as the correct value of the function; if the integer expression math_errhandling & MATH_ERRNO is nonzero, the integer expression errno acquires the value ERANGE; if the integer expression math_errhandling & MATH_ERREXCEPT is nonzero, the ''divide-by-zero'' floating-point exception is raised if the mathematical result is an exact infinity and the ''overflow'' floating-point exception is raised otherwise.

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It is also difficult to check for math errors using {{errno}} because an implementation might not set it. For real functions, the programmer can tell whether the implementation sets {{errno}} by checking whether {{math_errhandling & MATH_ERRNO}} is nonzero. For complex functions, the C99 Section 7.3.2 simply states "an implementation may set {{errno}} but is not required to" \[[ISO/IEC 9899:1999|AA. References#ISOBibliography#ISO/IEC 9899-1999]\].

The System V Interface Definition, Third Edition (SVID3) provides more control over the treatment of errors in the math library. The user can provide a function named matherr that is invoked if errors occur in a math function. This function can print diagnostics, terminate the execution, or specify the desired return-value. The matherr() function has not been adopted by C99, so its use is not generally portable.

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\[[ISO/IEC 9899:1999|AA. References#ISOBibliography#ISO/IEC 9899-1999]\] Section 7.3, "Complex arithmetic <{{complex.h}}>", and Section 7.12, "Mathematics <{{math.h}}>"
\[[MITRE 07|AA. References#MITREBibliography#MITRE 07]\] [CWE ID 682|http://cwe.mitre.org/data/definitions/682.html], "Incorrect Calculation"
\[[Plum 85|AA. References#PlumBibliography#Plum 85]\] Rule 2-2
\[[Plum 89|AA. References#PlumBibliography#Plum 91]\] Topic 2.10, "conv - conversions and overflow"

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