A constant difference in a number pattern refers to the consistent value added or subtracted between consecutive terms in a sequence.
In simpler terms, if you subtract any term from the term that follows it, and you always get the same number, then that number is the constant difference. Such a sequence is called an arithmetic sequence.
Here's a breakdown:
-
Definition: A constant difference occurs when the difference between any two consecutive numbers in a sequence remains the same.
-
Arithmetic Sequence: A sequence with a constant difference is specifically called an arithmetic sequence or arithmetic progression.
-
Finding the Constant Difference: To find the constant difference, subtract any term from its subsequent term.
Constant Difference (d) = a(n+1) - a(n)
where
a(n+1)
is the next term anda(n)
is the current term.
Examples:
-
Example 1: Arithmetic Sequence with Addition
Consider the sequence: 2, 5, 8, 11, 14...
- 5 - 2 = 3
- 8 - 5 = 3
- 11 - 8 = 3
- 14 - 11 = 3
The constant difference is 3. Each term is obtained by adding 3 to the previous term.
-
Example 2: Arithmetic Sequence with Subtraction
Consider the sequence: 20, 15, 10, 5, 0...
- 15 - 20 = -5
- 10 - 15 = -5
- 5 - 10 = -5
- 0 - 5 = -5
The constant difference is -5. Each term is obtained by subtracting 5 from the previous term.
Key Characteristics:
-
Linear Growth/Decline: Arithmetic sequences exhibit linear growth (addition) or decline (subtraction). This is because the value changes by a fixed amount each time.
-
Predictability: Because the difference is constant, you can predict future terms in the sequence.
-
Formula: The general formula for the nth term of an arithmetic sequence is:
a(n) = a(1) + (n - 1)d
where:
a(n)
is the nth terma(1)
is the first termn
is the term numberd
is the constant difference
In summary, a constant difference in a number pattern indicates a predictable and linear relationship between the terms, forming an arithmetic sequence.