Math Problem Statement

answer an give me the sequence formula for the tables

answer and give me the sequence formula for the tables

Solution

Let's start by analyzing the two problems presented.

Problem 1:

The sequence provided is:
100, 50, 25, 12.5, ___, ___

This is a geometric sequence because each term is obtained by multiplying the previous term by a constant ratio. Let's find that ratio:

50100=0.5\frac{50}{100} = 0.5 2550=0.5\frac{25}{50} = 0.5 12.525=0.5\frac{12.5}{25} = 0.5

The common ratio r=0.5r = 0.5.

Now, let's fill in the next two terms:

12.5×0.5=6.2512.5 \times 0.5 = 6.25 6.25×0.5=3.1256.25 \times 0.5 = 3.125

The complete sequence is:
100, 50, 25, 12.5, 6.25, 3.125

Table for Problem 1:

nt(n)
1100
250
325
412.5
56.25
63.125

Sequence Formulas for Problem 1:

  1. Explicit formula (General term for the sequence):
    t(n)=100×(0.5)n1t(n) = 100 \times (0.5)^{n-1}

  2. Recursive formula:
    t(1)=100t(1) = 100 t(n)=t(n1)×0.5,for n>1t(n) = t(n-1) \times 0.5, \quad \text{for } n > 1


Problem 2:

The sequence provided is:
8, 3, -2, -7, ___, ___

This is an arithmetic sequence because the difference between consecutive terms is constant. Let's find the common difference dd:

38=53 - 8 = -5 23=5-2 - 3 = -5 7(2)=5-7 - (-2) = -5

The common difference d=5d = -5.

Now, let's fill in the next two terms:

75=12-7 - 5 = -12 125=17-12 - 5 = -17

The complete sequence is:
8, 3, -2, -7, -12, -17

Table for Problem 2:

nt(n)
18
23
3-2
4-7
5-12
6-17

Sequence Formulas for Problem 2:

  1. Explicit formula (General term for the sequence):
    t(n)=8+(n1)(5)t(n) = 8 + (n - 1)(-5) or
    t(n)=85(n1)t(n) = 8 - 5(n - 1)

  2. Recursive formula:
    t(1)=8t(1) = 8 t(n)=t(n1)5,for n>1t(n) = t(n-1) - 5, \quad \text{for } n > 1


Would you like more details on the sequences, or have any other questions?

Additional Questions:

  1. How would you apply these sequence formulas to other similar problems?
  2. Can you describe the difference between geometric and arithmetic sequences?
  3. How do you identify whether a sequence is geometric or arithmetic from the terms?
  4. How would you extend these sequences further?
  5. What would happen if the sequence's common ratio or common difference was different?

Tip: Understanding the pattern of a sequence (whether it’s adding/subtracting or multiplying/dividing) is key to determining whether it's arithmetic or geometric, which will guide you in finding the correct formulas.

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Math Problem Analysis

Mathematical Concepts

Arithmetic Sequences
Geometric Sequences
Recursive Equations
Explicit Equations

Formulas

Explicit formula for geometric sequences: t(n) = a * r^(n-1)
Recursive formula for geometric sequences: t(1) = a, t(n) = t(n-1) * r for n > 1
Explicit formula for arithmetic sequences: t(n) = a + (n - 1) * d
Recursive formula for arithmetic sequences: t(1) = a, t(n) = t(n-1) + d for n > 1

Theorems

Geometric sequence property
Arithmetic sequence property

Suitable Grade Level

Grades 7-9