// minds behind maths
Roger Cotes
1682–1716 · Mathematics
Roger Cotes was an English mathematician, known for working closely with Isaac Newton on the second edition of the Principia. He introduced the concept now called the radian — measuring an angle by the length of arc it cuts on a circle of radius one — in work published after his early death. The unit makes the angle equal to its arc length, which simplifies the formulas of calculus and wave physics. The name 'radian' itself was coined much later, in 1873, by James Thomson, brother of Lord Kelvin.
Source: Wikipedia — Radian
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