Can anyone help with the verification that the final integral over infinity = 1?
Let X denote the vibratory stress (psi) on a wind turbine blade at a particular wind speed in a wind tunnel. The article “Blade Fatigue Life Assessment with Application to VAWTS” (J. Solar Energy Engr., 1982: 107-111) proposes the Rayleigh distribution, with pdf
f(x;
)=
for x>0 and 0 otherwise as a model for the X distribution.
a) Verify that f(x;
) is a legitimate pdf.
Rule 1: f(x)
. All powers of e are positive everywhere so it is left to show
is positive.
must be positive and x is always greater than or equal to zero. Therefore the function is non-negative.
Rule 2:
let u=
then du=
so
Is
= 1?? Or did I screw up royally? Or both?
The problem states that x is non-negative so the integral should go from 0 to