Here's a concise polynomial formula sheet ideal for a 10th grader, including key concepts and steps for solving polynomial problems.
Polynomial Basics
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Definition of a Polynomial: A polynomial is an expression that consists of variables and coefficients, using only the operations of addition, subtraction, multiplication, and non-negative integer exponents.
General Form:
\[ P(x) = a_n x^n + a_{n-1} x^{n-1} + ... + a_1 x + a_0 \]- \(P(x)\) = polynomial
- \(a_n\) = coefficient of \(x^n\)
- \(n\) = degree of the polynomial (highest exponent)
- \(x\) = variable
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Types of Polynomials:
- Monomial: One term (e.g., \(3x^2\))
- Binomial: Two terms (e.g., \(x^2 + 4\))
- Trinomial: Three terms (e.g., \(2x^2 + 3x + 1\))
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Degree of a Polynomial:
- The degree is determined by the highest exponent of the variable.
- Example: For \(2x^3 + 3x^2 + 5\), the degree is 3.
Operations with Polynomials
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Addition and Subtraction:
- Combine like terms.
- Example: \[ (3x^2 + 2x) + (4x^2 - 5) = (3x^2 + 4x^2) + (2x) - 5 = 7x^2 + 2x - 5 \]
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Multiplication:
- Use the distributive property (FOIL for binomials).
- Example: \[ (x + 2)(x + 3) = x^2 + 3x + 2x + 6 = x^2 + 5x + 6 \]
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Division:
- Polynomial long division or synthetic division.
Steps for Polynomial Long Division:
- Divide the leading term of the numerator by the leading term of the denominator.
- Multiply the entire denominator by this result and subtract from the numerator.
- Repeat until the degree of the remainder is less than the degree of the divisor.
Factoring Polynomials
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Factoring Out the Greatest Common Factor (GCF):
- Identify and factor out the GCF of all terms.
- Example:
\[ 6x^3 + 9x^2 = 3x^2(2x + 3) \]
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Factoring Trinomials:
- For \(ax^2 + bx + c\):
- Find two numbers that multiply to \(a \cdot c\) and add to \(b\).
- Example: Factor \(2x^2 + 7x + 3\):
- Multiply \(2 \cdot 3 = 6\)
- Find numbers: \(6\) and \(1\) (since \(6 + 1 = 7\))
- Write as: \[ 2x^2 + 6x + 1x + 3 = 2x(x + 3) + 1(x + 3) = (2x + 1)(x + 3) \]
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Difference of Squares:
- \(a^2 - b^2 = (a - b)(a + b)\)
- Example: \[ x^2 - 9 = (x - 3)(x + 3) \]
The Remainder and Factor Theorems
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Remainder Theorem:
- If a polynomial \(P(x)\) is divided by \(x - c\), the remainder is \(P(c)\).
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Factor Theorem:
- \(x - c\) is a factor of \(P(x)\) if and only if \(P(c) = 0\).
Evaluating Polynomials
- Polynomial Evaluation:
- Substitute \(x\) in \(P(x)\) with the given value and calculate.
- Example: For \(P(x) = x^2 + 3x + 5\), to find \(P(2)\): \[ P(2) = 2^2 + 3(2) + 5 = 4 + 6 + 5 = 15 \]
Graphing Polynomials
- Key Points:
- Find roots (x-intercepts) by setting \(P(x) = 0\).
- Determine end behavior based on the leading coefficient and degree (even/odd).
Summary
- Understanding polynomial operations, factoring, and evaluation is key to mastering higher algebra.
- Practice problems regularly to reinforce these concepts.