Being able to solve inequalities is important to be able to graph functions because you’ll often want to know when the derivative f’(x) is greater than 0 (meaning the original function f(x) is increasing) or less than 0 (meaning the original function f(x) is decreasing). Arun articulates this important concept, and Katie walks you through examples of solving inequalities.

**Lesson 2: Solving equations and inequalities**

- Why solve equations?
- Solving equations: Quadratics
- Exercises: Solve quadratic equations
- Solving equations: Absolute values
- Exercises: Solve equations involving absolute value
- Solving equations: Polynomials
- Exercises: Solve polynomial equations
- Solving equations: Rational expressions
- Exercises: Solve equations involving rational expressions
- Solving equations: Exponents
- Exercises: Solve exponential equations
- Solving equations: Logs
- Exercises: Solve logarithmic equations
- Solving equations: Trigonometric functions
- Trig identities
- Exercises: Solve trigonometric equations
- Why solve inequalities?
- Solving inequalities 📝
- Exercises: Solve inequalities