Math Problem Statement

limite de cette suite

Solution

The sequence given in the image is:

un=2n+1n+325u_n = \frac{2n + 1}{n + 325}

To find the limit of this sequence as nn approaches infinity (nn \to \infty), let's analyze it step by step.

Step 1: Divide Numerator and Denominator by nn

un=2n+1n+325=2n/n+1/nn/n+325/n=2+1n1+325nu_n = \frac{2n + 1}{n + 325} = \frac{2n/n + 1/n}{n/n + 325/n} = \frac{2 + \frac{1}{n}}{1 + \frac{325}{n}}

Step 2: Evaluate the Limit as nn \to \infty

As nn becomes very large, the terms 1n\frac{1}{n} and 325n\frac{325}{n} approach 0. So, the expression simplifies to: limnun=2+01+0=21=2\lim_{n \to \infty} u_n = \frac{2 + 0}{1 + 0} = \frac{2}{1} = 2

Conclusion:

The limit of the sequence unu_n as nn approaches infinity is 22.

Do you need further details or have any other questions?

Here are five related questions to expand on this topic:

  1. How does the limit of a sequence relate to the concept of convergence?
  2. Can you apply the same method to find the limit of a different sequence, like 3n2+nn2+5n+1\frac{3n^2 + n}{n^2 + 5n + 1}?
  3. What happens if the sequence includes higher powers of nn in the numerator or denominator?
  4. How does the presence of constants, like 325 in the denominator, affect the limit?
  5. What is the significance of determining the limit of a sequence in mathematical analysis?

Tip: When finding the limit of a sequence, dividing both the numerator and the denominator by the highest power of nn often simplifies the expression and makes it easier to determine the limit.