IXL - Write formulas for arithmetic and geometric sequences: function notation (Algebra 1 practice)

Write an expression to describe the sequence below. Use n to represent the position of a term in the sequence, where n = 1 for the first term.

^–3, ^–2, ^–1, 0, ...

f(n) =

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question

Write an expression to describe the sequence below. Use n to represent the position of a term in the sequence, where n = 1 for the first term.

62, 124, 186, 248, ...

f(n) =

solution

The sequence 62, 124, 186, 248, ... looks like 1, 2, 3, 4, ... except each term is 62 times as large. So, the expression that describes the sequence is 62n, where n represents the position of a term in the sequence. Check the first four terms:

To find the 1^st term, plug in n = 1.

62n = 62(1) = 62

To find the 2^nd term, plug in n = 2.

62n = 62(2) = 124

To find the 3^rd term, plug in n = 3.

62n = 62(3) = 186

To find the 4^th term, plug in n = 4.

62n = 62(4) = 248

The sequence 62, 124, 186, 248, ... is described by the expression 62n.

Looking for more? Try these:

Lesson: Geometric sequences

Lesson: Arithmetic sequences

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Write formulas for arithmetic sequences: function notation

Write formulas for geometric sequences: function notation

Lesson: Geometric sequences

Lesson: Arithmetic sequences

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