Trigonometry B — Waves & the Triangle Laws
Part 2 of 2. Sine waves (amplitude, frequency, period), the Pythagorean identity, and the laws of cosines & sines for any triangle.
Part 2 of 2. Walking around the unit circle traces a wave — and the same sine and cosine crack open any triangle, not just right ones.
- 01 Sine waves ELI5: walk around the circle at a steady pace and plot your height over time — you get a sine wave. Two knobs shape it: amplitude stretches it tall angular…
- 02 Any triangle: the law of cosines ELI5: the law of cosines is Pythagoras with a correction for when the angle isn't 90°. Two sides and the angle between them give the third: c² = a² + b² −…
- 03 Any triangle: the law of sines ELI5: the law of sines says each side is proportional to the sine of the angle across from it: sin(A)/a = sin(B)/b. Know one matched side–angle pair plus one…
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