- High school📊Trigonometry🔵
Trig circle: the 4 values to memorize (0°, 30°, 45°, 60°, 90°)
One raised hand, five fingers, five angles. The mnemonic to remember cos and sin of all usual angles.
- High school📊Trigonometry🔵
cos²(x) + sin²(x) = 1: Pythagoras in disguise
The most-used trig identity of high school is nothing but Pythagoras applied to the unit circle. Proof in 30 seconds.
