若a,x1,x2,x3,b与a,y1,y2,y3,y4,y5,b均成等差数列,求(x3-x1)/(y3-y1)
问题描述:
若a,x1,x2,x3,b与a,y1,y2,y3,y4,y5,b均成等差数列,求(x3-x1)/(y3-y1)
过程详细点
答
a,x1,x2,x3,b等差d1则b-a=4d1而x3-x1=2d1=(b-a)/2
a,y1,y2,y3,y4,y5,b等差d2则b-a=6d2而y3-y1=2d2=(b-a)/3
所以(x3-x1)/(y3-y1)=[(b-a)/2]/[(b-a)/3]=3/2=1.5