y=x^(3/2)、x^y=y^x　⇔　x^{x^(3/2)}=x^(3x/2)、x^{x^(3/2)-(3x/2)}=1、{x^(3/2)-(3x/2)}*log(x)=0
log(x)=0　⇔　x=1, y=1、x^(3/2)-(3x/2)=0　⇔　x^2(4x-9)=0、x=9/4, y=27/8