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.

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.

To find the sum of an infinite geometric series, you can use the formula:

Sum = a_1 / (1 - r)

Where:
- Sum is the sum of the series
- a_1 is the first term of the series
- r is the common ratio

In your case, the first term (a_1) is 4, and the common ratio (r) is 1/4.

Now substitute these values into the formula:

Sum = 4 / (1 - 1/4)

To simplify the expression, you need to find a common denominator for the fraction in the denominator:

Sum = 4 / (4/4 - 1/4)

Sum = 4 / (3/4)

To divide fractions, you can multiply by the reciprocal of the second fraction:

Sum = 4 * (4/3)

Simplifying the expression further:

Sum = 16/3

So, the sum of the infinite geometric series 4 + 1 + 1/4 + ... is 16/3.