M={-11,-7,0,1,2,3,5}直线ax+by+c=0倾斜角为钝角的概率

问题描述:

M={-11,-7,0,1,2,3,5}直线ax+by+c=0倾斜角为钝角的概率

c21*c41/p73(P73就是A73)=1/35