E(X)=∫(0~1)ax^a dx=a/(a+1)a/(a+1)=Xbara=aXbar+Xbara=Xbar/(1-Xbar)Maxium likelihood estimation:L(a)=a^n {∏xi^(a-1)}l(a)=nlna+(a-1)∑(lnxi)求导l'(a)=n/a+∑(lnxi) 0=n/^a+∑(lnxi) ^a=-n/∑(lnxi)
