prime factor
(noun)
A factor of a given integer that is also a prime number.
Examples of prime factor in the following topics:
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Factors
- Such prime numbers are called prime factors.
- Therefore, 2 and 3 are prime factors of 6.
- However, 6 is not a prime factor.
- In this case, we must reduce 6 to its prime factors as well.
- We have now found factors for 12 that are all prime numbers.
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Rational Algebraic Expressions
- For each of the denominators, we find all the prime factors—i.e., the prime numbers that multiply to give that number.
- If you are not familiar with the concept of prime factors, it may take a few minutes to get used to. $2\cdot 2 \cdot 3$ is $12$ broken into its prime factors: that is, it is the list of prime numbers that when multiplied together yield 12.
- Similarly, the prime factors of 30 are 2, 3, and 5.
- Similarly, any number whose prime factors include a 2, a 3, and a 5 will be a multiple of 30.
- Finding the prime factors of the denominators of two fractions enables us to find a common denominator.
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Introduction to Factoring Polynomials
- Factoring by grouping divides the terms in a polynomial into groups, which can be factored using the greatest common factor.
- Factor out the greatest common factor, $4x(x+5) + 3y(x+5)$.
- The aim of factoring is to reduce objects to "basic building blocks", such as integers to prime numbers, or polynomials to irreducible polynomials.
- One way to factor polynomials is factoring by grouping.
- Both groups share the same factor $(x+5)$, so the polynomial is factored as:
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Inverses of Composite Functions
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Factoring General Quadratics
- We can factor quadratic equations of the form $ax^2 + bx + c$ by first finding the factors of the constant $c$.
- This leads to the factored form:
- First, we factor $a$, which has one pair of factors 3 and 2.
- Then we factor the constant $c$, which has one pair of factors 2 and 4.
- Using these factored sets, we assemble the final factored form of the quadratic
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Common Bases of Logarithms
- They describe musical intervals, appear in formulas counting prime numbers, inform some models in psychophysics, and can aid in forensic accounting.
- Natural logarithms are closely linked to counting prime numbers ($2, 3, 5, 7$ ...), an important topic in number theory.
- The prime number theorem states that for large enough N, the probability that a random integer not greater than N is prime is very close to $\frac {1} {log(N)}$.
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Factoring Perfect Square Trinomials
- When a trinomial is a perfect square, it can be factored into two equal binomials.
- It is important to be able to recognize such trinomials, so that they can the be factored as a perfect square.
- If you are attempting to to factor a trinomial and realize that it is a perfect square, the factoring becomes much easier to do.
- Since the middle term is twice $4 \cdot x$, this must be a perfect square trinomial, and we can factor it as:
- Evaluate whether a quadratic equation is a perfect square and factor it accordingly if it is
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Finding Factors of Polynomials
- When factoring, things are pulled apart.
- There are four basic types of factoring.
- The common factor is $3$.
- This is the simplest kind of factoring.
- Therefore it factors as $(x+5)(x-5)$.
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Solving Quadratic Equations by Factoring
- To factor an expression means to rewrite it so that it is the product of factors.
- The reverse process is called factoring.
- Factoring is useful to help solve an equation of the form:
- Again, imagine you want to factor $x^2-7x+12$.
- We attempt to factor the quadratic.
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Finding Zeros of Factored Polynomials
- The factored form of a polynomial reveals its zeros, which are defined as points where the function touches the $x$-axis.
- The factored form of a polynomial can reveal where the function crosses the $x$-axis.
- In general, we know from the remainder theorem that $a$ is a zero of $f(x)$ if and only if $x-a$ divides $f(x).$ Thus if we can factor $f(x)$ in polynomials of as small a degree as possible, we know its zeros by looking at all linear terms in the factorization.
- This is why factorization is so important: to be able to recognize the zeros of a polynomial quickly.
- Use the factored form of a polynomial to find its zeros