Trigonometry The mathematics of angles, from zero: three ratios that unlock every right triangle, the two special triangles behind all exact values, the unit circle and its wave, the identities that connect them — and the laws of sines and cosines that solve ANY triangle. Nearly every step comes with a diagram you can read the answer from.
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The course — 6 units, in order
01 Right-Triangle Trigonometry SOH-CAH-TOA: name the sides, pick the ratio, solve for any missing side or angle — then aim it at towers, ramps, and shadows. Start 02 Special Triangles & Exact Values Half a square and half an equilateral: the two triangles behind every exact value of 30°, 45°, and 60°. Start 03 Radians & the Unit Circle Angles measured by arc, a circle where cosine and sine ARE the coordinates — and exact values in every quadrant. Start 04 Graphs of Trig Functions The circle unrolled into a wave: amplitude, period, phase, midline — and tangent's wilder portrait. Start 05 Identities & Equations The Pythagorean identity, sum and double-angle formulas — and solving equations whose unknown is an angle. Start 06 Laws of Sines & Cosines Trigonometry for EVERY triangle: the sine area formula, both laws, and the strategy for solving any triangle from any three facts. Start