How to determine the infinite sum of a geometric series

The video tutorial explains how to find the sum of an infinite geometric sequence using a specific formula. It begins by introducing the formula and identifying the first term and common ratio of the sequence. The tutorial then demonstrates how to calculate the sum by plugging these values into the formula, resulting in a simplified final answer. The video concludes with a summary of the process.

What is the formula used to find the sum of an infinite geometric sequence?

• S = a - r

• S = a / (1 - r)

• S = a * r

• S = a + r

In a geometric sequence, what does the term 'a sub 1' represent?

• The sum of the sequence

• The last term

• The first term

• The common ratio

How is the common ratio 'r' determined in a geometric sequence?

• By adding the first and second terms

• By dividing the second term by the first term

• By multiplying the first and second terms

• By subtracting the first term from the second term

What is the value of the common ratio 'r' in the given sequence?

• 0.1

• 0.9

• 0.8

• 1.0

What is the final simplified sum of the infinite geometric sequence in the example?

• 0.8

• 0.9

• 8/9

• 1.0