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1从学生一个作业题谈起作业题:向面积为S的△ABC内任投一点P,设△PBC的面积小于2S的概率为P(A),判断P(A)与12的大小.学生解法为:如图1,△ABC中,BC边上的高h,△PBC中,BC边上的高h1,由条件先考虑S△BCPS11221212BC×h,即h121h,设事件A:△PBC的面积小于2S.事件A发生只要h121h,?
1 from the students on a homework title on homework questions: △ ABC within the area for any investment in a point P, △ PBC area is less than 2S probability of P (A), to determine the size of P (A) and 12. Students Solution: as shown in Figure 1, △ ABC, BC edge of the high h, △ PBC, BC edge of the high h1, to be considered by the conditions S △ BCPS11221212BC × h, h121h, set the event A: △ PBC area Less than 2S. Event A occurs as long as h121h ,?