Z-Score Formula and Z Table (Standard Normal Table)
The z-score formula, how to read a z table, normal probabilities and percentiles, comparing scores, and a complete standard normal table.
Month: October 2026
Read article → Z-Score Formula and Z Table (Standard Normal Table)
Volume Formulas and Surface Area of 3D Shapes
Volume and surface area formulas for cubes, boxes, cylinders, cones, spheres and pyramids, why they work, unit conversions and examples.
Velocity, Acceleration and Displacement: Formulas and Graphs
Velocity, acceleration and displacement explained: average and instantaneous formulas, motion graphs, calculus links and worked examples.
The Unit Circle: Angles, Coordinates and Trig Values
The unit circle explained: why the coordinates are cos and sin, every special angle in degrees and radians, tangent on the unit circle, and memory tricks.
Trigonometric Functions: Sin, Cos, Tan, Table and Graphs
The six trig functions with SOH-CAH-TOA and the unit circle, a table of exact values (sin 30, cos 180, sec 45), graphs, period and amplitude.
Trig Identities: Full List with Double Angle Formulas
Every trig identity you need: Pythagorean, reciprocal, sum and difference, double angle and half angle formulas, with proofs and worked examples.
Standard Deviation Formula: How to Calculate It, Step by Step
The standard deviation formula for samples and populations, a step-by-step method, variance, the 68-95-99.7 rule, grouped data, and worked examples.
Special Right Triangles: 45-45-90 and 30-60-90 Rules
The 45-45-90 and 30-60-90 special right triangles: side ratios, where they come from, how to find missing sides, exact trig values and practice problems.
Slope Formula: Point-Slope and Slope-Intercept Form
How to find the slope of a line from two points, a graph or an equation, plus point-slope and slope-intercept form, parallel and perpendicular lines.
Quadratic Formula: Derivation, Discriminant, Examples
How to use the quadratic formula, where it comes from, what the discriminant tells you, how to find the vertex of a parabola, plus practice problems.