Math Problem Statement

I think the answer to number 2 is wrong. The given are 1, 1/5, 1/25..

Solution

Thank you for pointing that out! Let's revisit option (b) with the correct sequence.

(b) 1,15,125,1125,1, \frac{1}{5}, \frac{1}{25}, \frac{1}{125}, \dots

This is a geometric series where:

  • The first term a=1a = 1.
  • The common ratio r=151=15r = \frac{\frac{1}{5}}{1} = \frac{1}{5}.

Since r=15<1|r| = \frac{1}{5} < 1, the sum to infinity exists and is given by: S=a1r=1115=145=54=1.25S_{\infty} = \frac{a}{1 - r} = \frac{1}{1 - \frac{1}{5}} = \frac{1}{\frac{4}{5}} = \frac{5}{4} = 1.25 So, the correct sum to infinity for this series is 1.25.

Corrected Conclusion:

  • For series (a), the sum to infinity does not exist.
  • For series (b), the sum to infinity is 1.25.
  • For series (c), the sum to infinity is 1.6.

I appreciate your attention to detail! Do you have any further questions or need additional explanations?

Related Questions:

  1. What is the formula for the sum to infinity of a geometric series?
  2. How do you determine if a series is geometric?
  3. Can a geometric series with a negative common ratio converge?
  4. What are some real-life applications of geometric series?
  5. How does the value of the common ratio affect the sum to infinity?

Tip:

When working with geometric series, carefully check the common ratio and ensure you use the correct terms for calculating the sum to infinity.