IndietroCollege Algebra: Foundations, Equations, and Inequalities
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CHAPTER R: Review of Algebraic Foundations
R.4 Polynomials
Polynomials are algebraic expressions consisting of variables and coefficients, combined using only addition, subtraction, multiplication, and non-negative integer exponents. Understanding polynomials is essential for manipulating algebraic expressions and solving equations.
Definition: A polynomial is an expression of the form , where the coefficients are real numbers and is a non-negative integer.
Degree: The highest exponent of the variable in the polynomial.
Standard Form: Terms are written in descending order of exponents.
Example: is a polynomial of degree 4.
R.5 Factoring Polynomials
Factoring is the process of expressing a polynomial as a product of its factors. This skill is crucial for simplifying expressions and solving polynomial equations.
Common Factoring Methods:
Factoring out the greatest common factor (GCF)
Factoring trinomials
Difference of squares:
Sum/difference of cubes
Example:
R.7 Rational Expressions
Rational expressions are fractions where the numerator and denominator are both polynomials. Simplifying and operating with rational expressions is foundational for advanced algebraic manipulation.
Definition: A rational expression is an expression of the form , where and are polynomials and .
Key Skills: Simplifying, multiplying, dividing, adding, and subtracting rational expressions.
Example: (for )
R.8 Roots & Radicals
Roots and radicals involve expressions with fractional exponents or radical signs. Mastery of these concepts is necessary for solving equations and simplifying expressions.
Definition: The n-th root of is a number such that .
Radical Notation:
Properties: ,
Example:
CHAPTER 1: Equations & Inequalities
1.1 Linear Equations
Linear equations are equations of the first degree, meaning the variable is raised only to the first power. They are foundational for algebraic problem-solving.
General Form:
Solution: , where
Example:
1.2 Quadratic Equations
Quadratic equations involve the variable raised to the second power. They are solved using factoring, completing the square, or the quadratic formula.
Standard Form:
Quadratic Formula:
Example:
1.3 Complex Numbers
Complex numbers extend the real numbers to include solutions to equations like . They are written in the form .
Definition:
Form: , where and are real numbers
Example:
1.4 Radical Equations
Radical equations are equations in which the variable appears under a radical sign. Solving these often involves isolating the radical and raising both sides to a power.
Example:
Check for extraneous solutions after solving.
1.5 Solving Inequalities
Inequalities compare two expressions and use symbols such as , , , or . Solutions are often represented on a number line or in interval notation.
Linear Inequality Example:
Quadratic Inequality Example: or
1.6 Equations & Inequalities Involving Absolute Value
Absolute value equations and inequalities involve expressions like . The absolute value of a number is its distance from zero on the number line.
Definition: if , if
Equation Example: or
Inequality Example:
1.7 Problem Solving: Interest & Mixture
These problems apply algebraic equations to real-world contexts such as finance and chemistry.
Simple Interest Formula: , where is interest, is principal, is rate, and is time.
Mixture Problems: Use equations to represent the total amount and concentration of solutions mixed together.
Example: Mixing two solutions of different concentrations to achieve a desired concentration.