Math Problem Statement

Find the recursive definition of this sequence. 6, 12, 24, 48

Solution

The given sequence is 6,12,24,486, 12, 24, 48. Let's determine its recursive definition.

Steps:

  1. Look for the pattern:
    To find the recursive relation, we compare successive terms:

    • 12÷6=212 \div 6 = 2
    • 24÷12=224 \div 12 = 2
    • 48÷24=248 \div 24 = 2
      This shows that each term is double the previous term.
  2. Write the recursive formula:
    The formula can be expressed as:
    an=2an1,with a1=6a_n = 2a_{n-1}, \quad \text{with } a_1 = 6

  3. Validate:

    • a2=2a1=2×6=12a_2 = 2a_1 = 2 \times 6 = 12
    • a3=2a2=2×12=24a_3 = 2a_2 = 2 \times 12 = 24
    • a4=2a3=2×24=48a_4 = 2a_3 = 2 \times 24 = 48
      The formula works.

Answer:

The recursive definition of the sequence is:

a_n &= 2a_{n-1}, \\ a_1 &= 6 \end{aligned}}$$ This matches the third option provided in the image. Do you want further clarification or details? --- ### Related Questions: 1. What is the difference between a recursive and an explicit formula for a sequence? 2. Can you generalize this sequence to find the explicit formula? 3. How would the recursive formula change if the sequence were $$6, 18, 54, \ldots$$? 4. What are common applications of recursive sequences in real-world problems? 5. How would the recursive formula look if the first term were changed to $$a_1 = 3$$? ### Tip: When working with recursive sequences, always validate by substituting terms to ensure the formula holds!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Sequences
Recursive Formulas

Formulas

a_n = 2a_{n-1}, a_1 = 6

Theorems

Arithmetic and Geometric Sequences

Suitable Grade Level

Grades 6-8