- Second derivative test
- Seed
- Seedling
- Select strategies for adding within 100
- Semiconductor Devices
- Sensei
- Separable differential equations
- Sequoia
- Serendipity
- Series resisters
- Series resistors
- Series resistors (article)
- Series resistors (video)
- Series resistors notes
- Shaded areas
- Shape of distributions
- Shift and scale parabolas
- Shift functions
- Shifting and reflecting functions
- Shortest videos on KA
- Showcase
- Sign convention for passive components
- Sign convention for passive components and sources
- Significant figures
- Signs of products and quotients
- Signs of sums
- Silver Knowledge Games
- Simple hypothesis testing
- Simple probability
- Simplify numerical radical expressions with multiple terms
- Simplify numerical radical terms
- Simplify powers of the imaginary unit
- Simplify rational expressions by canceling binomial factors
- Simplify rational expressions by canceling monomial factors
- Simplify rational expressions using advanced factorization methods
- Simplify square roots of negative numbers
- Simplifying expressions with exponents
- Simplifying fractions
- Simplifying hairy fractions
- Simplifying rational expressions 2
- Simplifying rational expressions 3
- Simplifying rational expressions 4
- Simplifying rational expressions with exponent properties
- Simplifying resistor networks (article)
- Simplifying resistor networks (video)
- Simplifying square roots
- Simplifying square roots 2
- Sine and cosine come from circles
- Sine and cosine from rotating vector
- Sine of time
- Single-step simplification of radical expressions
- Single-step simplification of rational exponent expressions
- Sketching exponentials
- Sketching exponentials - examples
- Skip-count by 10s
- Skip-count by 5s
- Skip-counting by 100s
- Slicing 3D figures
- Slope-intercept equation from a graph
- Slope-intercept equation from two solutions
- Slope and triangle similarity
- Slope fields
- Slope from a graph
- Slope from an equation in slope-intercept form
- Slope from an equation in standard form
- Slope from two solutions
- Slope intuition
- Slope of secant lines
- Sneak Peek
- Solid geometry
- Solutions to quadratic equations
- Solve any system of two linear equations
- Solve equations with one rational expression (advanced)
- Solve equations with one rational expression (basic)
- Solve equations with two rational expressions
- Solve exponential equations using logarithms (base-10 and base-e)
- Solve exponential equations using logarithms (base-2 and other bases)