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### Course: Algebra 2 > Unit 3

Lesson 7: Geometric series- Geometric series introduction
- Finite geometric series formula
- Worked examples: finite geometric series
- Geometric series formula
- Geometric series word problems: swing
- Geometric series word problems: hike
- Finite geometric series word problems
- Polynomial factorization: FAQ

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# Polynomial factorization: FAQ

Frequently asked questions about polynomial factorization

## What is factoring?

Factoring is the process of breaking down a polynomial into smaller pieces (or "factors") that, when multiplied together, will give you the original polynomial.

## Why do we factor polynomials?

Factoring is a useful technique for solving polynomial equations. By breaking a polynomial down into smaller factors, we can often simplify the equation and find the solutions more easily.

## What is a monomial?

A monomial is a polynomial with just one term. For example, $2x$ , $-3{y}^{2}$ , and $5$ are all monomials.

## What is the greatest common factor?

The greatest common factor (GCF) of two or more terms is the largest factor that all the terms have in common. For example, the GCF of $6{x}^{2}$ and $9x$ is $3x$ .

## How do we take common factors out of a polynomial?

To take common factors out of a polynomial, we divide each term by the GCF. For example, to factor $6{x}^{2}+9x$ , we divide both terms by the GCF, $3x$ , to get $3x(2x+3)$ .

## What are polynomial identities?

Polynomial identities are equations that are true for all values of the variable. For example, the difference of squares identity, ${a}^{2}-{b}^{2}=(a+b)(a-b)$ , is true for any values of $a$ and $b$ .

## Where are these topics used in the real world?

There are many applications for factoring polynomials. For example, engineers may use these techniques in signal processing or control theory, while scientists might use them in modeling physical phenomena.

## Want to join the conversation?

- does this finite geo series formula always work? or is there a specific restriction for the variables?(4 votes)
- Geometric series always work except where common ratio = r = 1, since the denominator will be zero. But when r = 1, you can easily claim that all terms in the series are equal.

Other than that, the geometric series will always work.(27 votes)

- Can anyone explain geometric series in simple lang(2 votes)
- A geometric series is a sequence of numbers that follow a pattern where each term is obtained by multiplying the previous term by a fixed number. For example, the sequence 1, 2, 4, 8, 16, … is a geometric series because each term is twice the previous term. The fixed number that we multiply by is called the common ratio.

The formula for finding the sum of an infinite geometric series is a / (1 - r), where a is the first term and r is the common ratio. If |r| < 1, then the sum of the series is finite and can be calculated using this formula. If |r| >= 1, then the series diverges and does not have a finite sum.

For example, consider the geometric series 1 + 2 + 4 + 8 + .... Here, a = 1 and r = 2. Since |r| >= 1, this series diverges and does not have a finite sum.(15 votes)

- why is it when r is a percentage, it can be written as 1.the percentage or 0.the percentage? for example 10% was converted to 1.1 and not 0.1 but 90% was 0.9 and not 1.9(3 votes)
- Because if it is an increase like: the mall gained ten percent more customers than yesterday, you would have to write it as 1.1 instead of 0.1 because it is an increase instead of a decrease. Hope this helps!(8 votes)

- No lie, if I wanna be a nurse what would this math have to do with anything?(3 votes)
- Yes you do. Nurses routinely use addition, fractions, ratios and algebraic equations each workday to deliver the right amount of medication.(5 votes)

- for the earlier section we used the formula where "a" was included numerator section but now im using it like this?

a(1-r^n/1-r)?(4 votes)- Both is correct, just two different ways of representation(3 votes)

- my brain is fried. Is there any way to make finite series easier, maybe some tips or tricks? I especially need help with finding the first term using the formula(3 votes)
- I don't use any "tricks" but I just ignore the 'a' in the equation until get the final fraction which I multiply to the other side of the equation to isolate the 'a'. Ex. 25/27 x a = 57. You multiply the 25/27 by its reciprocal which is 27/25 to cancel it and you do the same to the other side of the equation to isolate the a on its own.(1 vote)

- how do you find the minimum of a degree on a graph?(3 votes)
- I guess one has to basically reconstruct the function or try to fit another function that is similar or use a Taylor series expansion, which I guess is mentioned in college algebra.(0 votes)

- I had troubles with understanding this section, it was completely out of the blue and the answers seemed to be random and did not match what the problem was. Could someone clarify the process for me?(2 votes)
- this is very very confusing help me please(1 vote)
- In deriving the geo series formula, why are the 2 lines added together? What is the reason? Tnx!(0 votes)
- They are equivalent expressions, and since they are equivalent, when you add one to the other, you are adding the same thing to both sides.

e.g.

a = 12

now lets square both sides to make another equation

a^2 = 12^2

now add both equations

a + a^2 = 12 + 12^2

it's still equivalent. Seems pointless here but as you saw from the video and you will see in the future, this allows us to manipulate equations in ways we couldn't do otherwise (e.g. in the geometric series, it allows us to add/subtract an infinitely repeating series to get a formula to solve for the variables in the series).(3 votes)