exp2, exp2f, exp2l - Exponential function

Definition	#include <math.h> double exp2(double x); (C11) float exp2f(float x); (C11) long double exp2l(long double x); (C11) These functions calculate the exponential function to the base 2 for permissible floating-point numbers x.
Returnwert	2 x	if successful.
	HUGE_VAL HUGE_VALF HUGE_VALL	depending on the function type, if an overflow occurs. errno is set to ERANGE (result too large).
See also	exp, log, log2, log10, pow