There are 10 terms in the geometric progression.

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In summary, the conversation is about finding the number of terms in a geometric progression with a starting value of 3 and a common ratio of 2, with the goal of reaching 1536 as the final term. The solution involved dividing 1536 by 3 and identifying it as a power of 2, leading to the conclusion that there are 10 terms in the progression. However, the original solution provided in the conversation contains errors and incorrect expressions.
  • #1
nae99
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Homework Statement



3,6,12...1536
determine the number of terms in the progression

Homework Equations





The Attempt at a Solution


a=3 r=2

n= ar^n-1

1536= (3) (2)^n-1
 
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  • #2
Okay, so solve it! First, divide both sides by 3. If that sequence is actually geometric, you should be able to identify 1536/3 as a power of 2. I suggest you just calculate powers of 2: 1, 2, 4, 8, 16, ... until you get to that number.
 
  • #3
HallsofIvy said:
Okay, so solve it! First, divide both sides by 3. If that sequence is actually geometric, you should be able to identify 1536/3 as a power of 2. I suggest you just calculate powers of 2: 1, 2, 4, 8, 16, ... until you get to that number.

1536= (3) (2)^n-1

1536/3 = 6^n-1[itex]/[/itex]3

512 = 2^n-1

512 = 2^10-1

512 = 2^9

n = 10
 
  • #4
nae99 said:
1536= (3) (2)^n-1

1536/3 = 6^n-1[itex]/[/itex]3

512 = 2^n-1

512 = 2^10-1

512 = 2^9

n = 10
There are errors in your work. Also, you need parentheses around your exponent expressions.
nae99 said:
1536= (3) (2)^(n-1)

1536/3 = 6^n-1[itex]/[/itex]3
The above is incorrect. 3*2^(n - 1) [itex]\neq[/itex] 6^(n - 1)
nae99 said:
512 = 2^n-1
The above is also incorrect. [6^(n - 1)]/3 [itex]\neq[/itex] 2^(n - 1)
nae99 said:
512 = 2^10-1

512 = 2^9

n = 10
 
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FAQ: There are 10 terms in the geometric progression.

What is a geometric progression?

A geometric progression is a sequence of numbers where each term is found by multiplying the previous term by a constant value called the common ratio. For example, in the sequence 2, 6, 18, 54, the common ratio is 3.

How is a geometric progression different from an arithmetic progression?

In an arithmetic progression, each term is found by adding a constant value to the previous term. In a geometric progression, each term is found by multiplying a constant value to the previous term. Also, in a geometric progression, the common ratio does not have to be a whole number, unlike in an arithmetic progression.

What is the formula for finding the nth term of a geometric progression?

The formula for finding the nth term of a geometric progression is: an = a1 * rn-1, where an represents the nth term, a1 is the first term, and r is the common ratio.

How can geometric progressions be used in real life?

Geometric progressions can be used to model many real-life situations, such as population growth, compound interest, and the depreciation of assets. They can also be used in various branches of science, such as physics, chemistry, and biology, to describe processes that exhibit exponential growth or decay.

What is the sum of a finite geometric progression?

The sum of a finite geometric progression can be found using the formula: Sn = a1 * (1 - rn) / (1 - r), where Sn represents the sum of the first n terms, a1 is the first term, and r is the common ratio. If the common ratio is less than 1, the sum will approach a finite number as n approaches infinity.

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