Qlaudia

← All courses

Algebra II

  • Mathematics

Exponential, logarithmic, polynomial, rational, and radical functions extend linear and quadratic algebra to model complex real-world phenomena. Sequences, systems, trigonometric functions, and data analysis complete the preparation for Precalculus and quantitative fields.

Sign in to enroll$1028 lessons

What you'll learn

  • Exponential Functions and Growth ModelsA function of the form f(x) = a·b^x where the variable appears as an exponent, producing rapid accelerating change that models either growth when b > 1 or decay when 0 < b < 1.
  • Domain and Range of FunctionsThe domain is the complete set of input values for which a function produces a valid real output, while the range is the complete set of output values the function actually produces.
  • Graphing Polynomial FunctionsA method for sketching polynomial graphs by identifying end behavior, zeros, multiplicity, and turning points directly from the equation.
  • Function TransformationsAlgebraic modifications to a parent function using constants that shift, stretch, compress, or reflect the graph according to the form g(x) = a·f(b(x - h)) + k.
  • Polynomial Expressions and OperationsA polynomial is an expression built from variables and constants using only addition, subtraction, and multiplication with whole-number exponents, forming a closed system where operations on polynomials always yield polynomials.
  • Solving Polynomial EquationsA polynomial equation sets a polynomial expression equal to zero, and finding all roots is accomplished primarily through factoring and applying the Zero Product Property or using the quadratic formula for equations that don't factor nicely.
  • Complex NumbersAn extension of the real number system that includes the imaginary unit i, defined by i² = −1, which allows all quadratic equations to have solutions.
  • Radical Expressions and Rational ExponentsRadical expressions involving roots can be rewritten as rational exponents, allowing exponent rules to be applied to simplify complex expressions involving roots.
  • Factoring PolynomialsThe process of rewriting a polynomial as a product of simpler polynomials, which reverses multiplication and enables solving equations, simplifying expressions, and analyzing graphs.
  • Rational Expressions and OperationsA rational expression is a fraction whose numerator and denominator are both polynomials, and simplifying one involves factoring both parts completely and canceling common factors.
  • Unit Circle and Radian MeasureA circle with radius one centered at the origin used to define trigonometric functions and measure angles by arc length rather than degrees.
  • Systems of Linear Equations in Multiple VariablesA collection of two or more linear equations in the same variables whose solution is a set of values that satisfies every equation at once.
  • Systems Involving Quadratic EquationsA collection of equations where at least one is quadratic, typically solved by substitution or elimination to find points where all equations are simultaneously satisfied.
  • Solving Radical EquationsA radical equation contains a variable inside a root expression and is solved by isolating the radical, raising both sides to a matching power, and checking all solutions because the process can introduce extraneous solutions.
  • Graphing Rational FunctionsA method for sketching the graphs of functions written as ratios of polynomials by identifying vertical asymptotes, holes, and horizontal asymptotes.
  • Basic Trigonometric FunctionsSine, cosine, and tangent are functions defined on the unit circle that assign to any real-number angle its corresponding point's coordinates and ratios.
  • Solving Exponential and Logarithmic EquationsExponential and logarithmic equations are solved using the inverse relationship between exponents and logarithms, where taking a logarithm undoes an exponent and exponentiation undoes a logarithm.
  • Polynomial Long Division and Remainder TheoremPolynomial long division is an algorithm for dividing one polynomial by another to obtain a quotient and remainder, mirroring integer long division and connecting division to finding polynomial roots.
  • Arithmetic Sequences and SeriesAn ordered list of numbers where each consecutive pair differs by a constant value, which can be computed using either a recursive formula or an explicit closed-form formula.
  • Geometric Sequences and SeriesAn ordered list of numbers where each term after the first is obtained by multiplying the previous term by a fixed nonzero number called the common ratio.
  • Fundamental Theorem of AlgebraA theorem stating that every polynomial of degree n has exactly n roots in the complex number system when counted with their multiplicities.
  • Inverse FunctionsA function that reverses the action of another function by taking outputs back to their original inputs, existing only when the original function is one-to-one.
  • Logarithmic Functions and Their PropertiesThe inverse functions of exponentials that express exponents needed to reach a given number from a base, with domain restricted to positive real numbers.
  • Periodic Modeling with Trigonometric FunctionsSine and cosine functions model repeating cyclic behavior because their values repeat at regular intervals as the angle sweeps repeatedly around the unit circle.
  • Systems of InequalitiesA set of two or more inequalities whose solution is the region where all inequalities overlap simultaneously.
  • Solving Rational EquationsA rational equation contains fractions with polynomials in the denominator and is solved by identifying excluded values, clearing denominators using the least common denominator, and verifying solutions against the original equation.
  • Interpreting Data DistributionsThe process of summarizing a data set using measures of center (mean, median, mode) and spread (range, quartiles, standard deviation) to describe its typical value and variability.
  • Measures of Center and SpreadMeasures of center and measures of spread are single numbers that summarize a data set by indicating where its values are located and how far apart they are from that center.

About this course

Welcome to Algebra II

Algebra II is the course that connects the linear and quadratic algebra you mastered in Algebra I to the wider world of functions you will need for Precalculus, calculus, and quantitative work in science, engineering, economics, and beyond. Where Algebra I focused mainly on lines and parabolas, Algebra II asks: what happens when relationships are not linear or quadratic — when they curve like a rational function, grow explosively like an exponential, repeat like a wave, or depend on more than one changing variable at once? This overview maps out the territory you will travel this year so that each new topic feels like a piece of a larger, connected picture rather than an isolated skill.

Why this course matters

Most of the mathematics used to model real phenomena — population growth, radioactive decay, sound waves, compound interest, the spread of information, and the variability in scientific measurements — is not linear. Algebra II gives you the algebraic tools to describe, manipulate, and solve problems involving these more complex relationships. It also deepens your understanding of what a "solution" means: you will meet equations with no real solutions, equations with extra false solutions introduced by the solving process itself, and functions whose inverses undo one another in precise, checkable ways.

The major strands

1. Polynomial expressions, equations, and functions. You already know how to add, multiply, and factor simple polynomials. This year you extend that work to higher-degree polynomials, learn systematic division techniques (long division and synthetic division), and connect factoring to root-finding. The strand culminates in the Fundamental Theorem of Algebra, which tells you exactly how many roots (real or complex) a polynomial of a given degree must have — a powerful organizing idea that ties together factoring, graphing, and complex numbers.

2. Rational and radical expressions and functions. Just as fractions of numbers require common denominators and careful simplification, fractions of polynomials (rational expressions) require the same care, plus attention to values that make a denominator zero. Radical expressions and equations bring their own subtlety: squaring both sides of an equation can introduce extraneous solutions that must be checked and discarded.

3. Exponential and logarithmic functions. These two function families are inverses of one another, much like squaring and square-rooting. Exponential functions model growth and decay — population, money, radioactive material — while logarithms let you solve for an unknown exponent, which arises constantly in applied problems (for example, "how many years until this investment doubles?").

4. Systems of equations and inequalities. You extend the linear systems you solved in Algebra I to systems that mix lines with parabolas or other curves, and to systems with more than two variables. You will solve these both algebraically (substitution, elimination) and graphically, and you will represent regions satisfying multiple inequalities at once.

5. Sequences and series. A sequence is an ordered list of numbers following a pattern; a series is the sum of such a list. You will study two major patterns — arithmetic (constant difference) and geometric (constant ratio) — and see how geometric sequences connect directly back to exponential functions.

6. Introduction to trigonometric functions. Building on angles and the unit circle from Geometry, you will learn radian measure, define the sine and cosine functions for any real number using the unit circle, and use these functions to model periodic (repeating) phenomena such as tides or sound waves. This course does not cover advanced trigonometric identities or proofs — those belong to Precalculus.

7. Interpreting statistics and data distributions. You will summarize and interpret data sets, compare distributions using measures of center and spread, and think carefully about what statistical summaries can and cannot tell you about a population.

How the strands connect

These strands are not independent chapters to memorize separately — they reinforce one another. Factoring polynomials supports solving polynomial equations, which supports understanding function graphs. Exponential functions and geometric sequences share the same underlying structure (repeated multiplication). Radical equations and rational equations both require you to check for extraneous solutions, a theme that recurs whenever a solving step is not perfectly reversible. The figure below shows how the strands build toward the overarching goal of Precalculus readiness.

Polynomial Expressions & Equations Rational & Radical Functions Exponential & Logarithmic Functions Systems of Equations & Inequalities Sequences & Series Intro to Trigonometric Functions Interpreting Statistics & Data Precalculus Readiness

The six content strands of Algebra II each build algebraic fluency, and together they prepare you for Precalculus.

How to use this course

Each concept document you encounter will define new vocabulary before using it, walk through the reasoning behind a method (not just the steps), and give worked examples before asking you to practice. Because this course assumes you are comfortable with Algebra I (solving linear equations, basic factoring, graphing lines) and basic Geometry (angles, the coordinate plane), those topics will only be reviewed briefly when they are needed to introduce something new — the focus stays on the new material. Keep in mind that many topics reappear later in a new form: factoring returns when solving polynomial equations, exponents return when studying logarithms, and the unit circle from Geometry returns when defining trigonometric functions. Building genuine understanding early will make each later topic easier to learn.

Algebra II — Qlaudia