cscX is equivalent to 1/sinX. Cosecant (csc) is the reciprocal of the sine of an angle in a right triangle.
In a right triangle, the cosecant of an angle is the length of the hypotenuse divided by the length of the opposite side. In a formula, it is abbreviated to just 'csc'. Of the six possible trigonometric functions, cosecant, cotangent, and secant, are rarely used. In fact, most calculators have no button for them, and software function libraries do not include them.
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