When you make x small, like .01, sin(x) gets small as well. And the ratio of sin(x)/x seems to be about .017 — what does that mean? Even stranger, what does it mean to multiply or divide by a degree? Can you have square or cubic degrees? Radians to the rescue! Knowing they refer to distance traveled (they’re not just a ratio!), we can interpret the equation this way: x is how far you traveled along a circle sin(x) is how high on the circle you are So sin(x)/x is the ratio of how high you are to how far you’ve gone: the amount of energy that went in an “upward” direction. If you move
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