c=［log(1/3) 4/3］/［log(1/3) 3］=［log(1/3) 4/3］/（-1）=-log(1/3) 4/3=log(1/3) 3/4因为此时a、b、c底数都为1/3，且0＜1/3＜1，为减函数1/2＜2/3＜3/4所以log(1/3) 1/2＞log(1/3) 2/3＞log(1/3) 3/4因此，a＞b＞c
