The Math.cos() function returns the cosine of a number.
Math.cos(x)
xThe Math.cos() method returns a numeric value between -1 and 1, which represents the cosine of the angle.
Because cos() is a static method of Math, you always use it as Math.cos(), rather than as a method of a Math object you created (Math is not a constructor).
Math.cos()Math.cos(0); // 1 Math.cos(1); // 0.5403023058681398 Math.cos(Math.PI); // -1 Math.cos(2 * Math.PI); // 1
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