Math Problem Statement

determine whether the sequence converges and if it converges find its limit a subscript n=((-1)^n)

Solution

The sequence given is an=(1)na_n = (-1)^n.

Let's analyze whether the sequence converges:

1. Behavior of the sequence:

The term (1)n(-1)^n alternates between 11 and 1-1 for successive values of nn. Specifically:

  • If nn is even, (1)n=1(-1)^n = 1.
  • If nn is odd, (1)n=1(-1)^n = -1.

Thus, the sequence alternates as follows:

  • For n=1n = 1, a1=1a_1 = -1
  • For n=2n = 2, a2=1a_2 = 1
  • For n=3n = 3, a3=1a_3 = -1
  • For n=4n = 4, a4=1a_4 = 1, and so on.

2. Convergence:

A sequence converges if, as nn approaches infinity, the terms of the sequence approach a single fixed value (the limit).

In this case, the sequence an=(1)na_n = (-1)^n does not approach a single value as nn \to \infty. Instead, it continues to alternate between 11 and 1-1, never settling on one particular value.

Therefore, the sequence does not converge.

Conclusion:

The sequence an=(1)na_n = (-1)^n does not converge, and hence, it has no limit.

Would you like further details or have any questions?

Here are five related questions you might consider:

  1. What is the definition of a convergent sequence?
  2. Can a sequence that alternates between two values ever converge?
  3. How do we mathematically prove that a sequence converges?
  4. What is an example of a sequence that converges to a limit?
  5. What is the difference between oscillating and converging sequences?

Tip: For a sequence to converge, the values of the sequence must get arbitrarily close to a specific number as nn \to \infty.

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Math Problem Analysis

Mathematical Concepts

Sequences
Convergence
Oscillating Sequences

Formulas

a_n = (-1)^n

Theorems

Definition of Convergence

Suitable Grade Level

Grades 10-12