lancecohen1986
lancecohen1986 3d ago • 0 views

Quick Guide: Calculating the Common Difference

Hey there! 👋 Ever been stuck trying to figure out if a sequence of numbers is following a pattern? 🤔 Well, the 'common difference' is your new best friend! Let's break it down together!
🧮 Mathematics

1 Answers

✅ Best Answer

📚 What is the Common Difference?

In simple terms, the common difference is the constant value added or subtracted in an arithmetic sequence. An arithmetic sequence is a list of numbers where the difference between any two consecutive terms is always the same. Think of it like climbing stairs where each step is the same height!

🧮 How to Calculate the Common Difference

To find the common difference ($d$), simply subtract any term from the term that follows it. Here's the formula:

$d = a_{n} - a_{n-1}$

Where:

  • 🔢 $d$ is the common difference
  • 📈 $a_{n}$ is any term in the sequence
  • 📉 $a_{n-1}$ is the term before $a_{n}$

✍️ Step-by-Step Example

Consider the arithmetic sequence: 2, 5, 8, 11, 14...

  1. Choose two consecutive terms: Let's pick 5 and 2.
  2. Subtract the first term from the second term: $5 - 2 = 3$
  3. Verify with another pair: Let's try 11 and 8. $11 - 8 = 3$

So, the common difference ($d$) is 3.

🆚 Common Difference vs. Common Ratio

It's easy to mix up common difference with common ratio. Let's clear up the confusion!

FeatureCommon DifferenceCommon Ratio
Definition➕ The constant value added/subtracted in an arithmetic sequence.➗ The constant value multiplied/divided in a geometric sequence.
Sequence Type➕ Arithmetic Sequence (e.g., 2, 4, 6, 8...)➗ Geometric Sequence (e.g., 2, 4, 8, 16...)
Calculation➖ Subtract a term from its subsequent term.➗ Divide a term by its preceding term.
Formula$d = a_{n} - a_{n-1}$$r = \frac{a_{n}}{a_{n-1}}$

🚀 Key Takeaways

  • Common Difference: Applies to arithmetic sequences.
  • Calculation: Subtraction between consecutive terms.
  • Common Ratio: Applies to geometric sequences (multiplication/division).

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