Find the sum of the infinite geometric series.

4+1+1/4+....
Sum=a_1/1-r
4/1-4=?
r=a_1/a_2
r=4/1=4
a_1=4
I am stuck?Please help me.

3 answers

r=1/4, a1=4, and a2=a1*r or r=a2/a1 I think that is where you went astray.

sum= 4/(1-1/4)=4/(3/4)=16/3
thank you bobpursley.
Why are you reposting the same question after it has been answered for you?
https://www.jiskha.com/questions/1770632/find-the-sum-of-the-infinite-geometric-series-4-1-1-4

This results in extra work by tutors, which should not be necessary.