SinCosTan
The Journal
Reading Amplitude, Period, Phase, and Midline Off a Sinusoid
Real oscillating data rarely arrives as a tidy equation. Here's how to reconstruct amplitude, period, phase shift, and midline from a handful of measurements, verified with the sine wave calculator.
Using Trig Identities to Actually Simplify an Expression
Knowing the identities and knowing when to reach for one are different skills. Six worked simplifications, each checked numerically against the trig identity calculator, show the process in full.
The Unit Circle: The One Idea Behind All of Trigonometry
Right-triangle ratios, the sine and cosine graphs, the Law of Cosines, and the angle-sum identities look like separate topics. They are all the same picture — a point moving around a circle of radius 1.