Maxima Function
std_exp (m)
Returns the standard deviation of an Exponential(m) random variable, with m>0.
The Exponential(m) random variable is equivalent to the Weibull(1,1/m), therefore when Maxima has not enough information to get the result, a noun form based on the Weibull standard deviation is returned.
(%i1) load (distrib)$ (%i2) std_exp(m); 1 (%o2) std_weibull(1, -) m (%i3) assume(m>0)$ std_exp(m); 1 (%o4) - m