Write a polynomial formula sheet like a 10th grader without any coding And with steps

1 answer

Here's a concise polynomial formula sheet ideal for a 10th grader, including key concepts and steps for solving polynomial problems.

Polynomial Basics

  1. 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
  2. Types of Polynomials:

    • Monomial: One term (e.g., \(3x^2\))
    • Binomial: Two terms (e.g., \(x^2 + 4\))
    • Trinomial: Three terms (e.g., \(2x^2 + 3x + 1\))
  3. 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

  1. Addition and Subtraction:

    • Combine like terms.
    • Example: \[ (3x^2 + 2x) + (4x^2 - 5) = (3x^2 + 4x^2) + (2x) - 5 = 7x^2 + 2x - 5 \]
  2. Multiplication:

    • Use the distributive property (FOIL for binomials).
    • Example: \[ (x + 2)(x + 3) = x^2 + 3x + 2x + 6 = x^2 + 5x + 6 \]
  3. 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

  1. Factoring Out the Greatest Common Factor (GCF):

    • Identify and factor out the GCF of all terms.
    • Example:
      \[ 6x^3 + 9x^2 = 3x^2(2x + 3) \]
  2. 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: \[ 2x^2 + 6x + 1x + 3 = 2x(x + 3) + 1(x + 3) = (2x + 1)(x + 3) \]
  3. Difference of Squares:

    • \(a^2 - b^2 = (a - b)(a + b)\)
    • Example: \[ x^2 - 9 = (x - 3)(x + 3) \]

The Remainder and Factor Theorems

  1. Remainder Theorem:

    • If a polynomial \(P(x)\) is divided by \(x - c\), the remainder is \(P(c)\).
  2. Factor Theorem:

    • \(x - c\) is a factor of \(P(x)\) if and only if \(P(c) = 0\).

Evaluating Polynomials

  1. 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

  1. 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.