SinCosTan
The Journal
How to Solve a Right Triangle
A step-by-step method for finding every unknown side and angle in a right triangle using the trig ratios, inverse functions, and the Pythagorean theorem.
SOHCAHTOA Explained: The Trig Ratios Made Simple
SOHCAHTOA is a six-letter memory trick that hands you the three core trig ratios, and this guide shows what each piece means with a worked example.
Law of Sines vs Law of Cosines: Which One to Use
A practical guide to choosing between the Law of Sines and the Law of Cosines, with the deciding rules and two short worked examples using real numbers.
Reading the Unit Circle
A guided tour of the unit circle, showing why each point is (cos, sin), listing the key angles and their exact values, and explaining the quadrant signs.
What Are Radians, and Why Mathematicians Prefer Them
Radians are the circle's own natural angle unit, and this article defines them from arc length, shows both conversions, and explains why calculus insists on them.
Graphing Sine and Cosine Waves
Learn to read amplitude, period, phase shift, and vertical shift straight off a sine or cosine equation, then sketch the wave without plotting points.
Common Trigonometric Identities You Should Know
A reference to the Pythagorean, reciprocal, quotient, even-odd, and angle-sum identities, closing with a full exact verification of sin 75 degrees.