Cotangent function. COT(x) returns the cotangent of x. The argument x must be expressed in radians. To convert degrees to radians you use the RADIANS function.
The cotangent is the reciprocal of the tangent:
The cotangent can be represented in terms of sine and cosine:
The argument x can be a real number or a matrix. When it is a matrix, the function returns a matrix with the same dimensions and with the COT function applied to all elements.
Trigonometry: A Complete Introduction
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