using wikipedia i found the correct answer (using the formulas that use the variance and such) but id still like to know how to recalculate it using the identities given so my question still stands :D
Homework Statement
f(x)=&(x-a)exp((-(x-a)^2)/b) where a and b are constants
Homework Equations
find & in terms of b:
show that the expected value of X is given by
X=a + sqrt(pi*b/4)
identity given
x(x-a)=(x-a)^2+a(x-a)
and integral from 0 to infinity of x^2*exp-x^2 dx=sqrt...