in a certain geometric sequence the first term exceeds the second term by 32 and the sum of the second and third is 48,f
问题描述：
in a certain geometric sequence the first term exceeds the second term by 32 and the sum of the second and third is 48,find the infinite sum of rhe sequence
答
一个几何级数中,第一项比第二项大32,第二项与第三项的和是48,求这个级数的无穷和.
设几何级数的前三项是a,aq,aq^2,则
a-aq=32,aq+aq^2=48,解得
a=8,q=-3,这时无穷和发散,
a=64,q=1/2,这时a+aq+aq^2+...=64/(1-1/2)=128.