Trigonometric Functions

Fathom Reference > Fathom Operators, Functions, and Units > Trigonometric Functions

Fathom knows about the six regular trigonometric functions and their inverses. It also knows about the six hyperbolic trig functions and their inverses, even though they are not listed in the formula editor.

Arguments for trig functions are assumed to be in radians if they don’t have units, but units may be explicitly specified, for example, sin(90deg) is 1. The inverse functions return radians, which may be converted to degrees: asin(1) is 1.57, and asin(1)*360deg/2π is 90 degrees.

Regular trig functions: sin, cos, tan, sec, csc, cot. The argument is in radians and the returned value has no units.

Inverses of regular trig functions: asin, acos, atan, asec, acsc, acot. The argument has no units and the returned values are in radians.

Hyperbolic trig functions: sinh, cosh, tanh, sech, csch, coth. The argument is in radians and the returned value has no units.

Inverse hyperbolic trig functions: asinh, acosh, atanh, asech, acsch, acoth. The argument has no units and the returned values are in radians.

atan2

Arctangent with two numeric arguments

Returns the angle in radians whose tangent is the second argument divided by the first where the signs of the two arguments determine which quadrant the angle is in: atan2(0.5,-1) is –1.107 radians;
atan2(-1,1)*360deg/2π is 135 degrees.