Calculates the inverse tangent of any expression.
A scalar, series or table.
A scalar, series, or table.
displays the inverse tangent from –12 to 12.
returns 0.78539816, or π/4.
returns 1.570796, or π/2.
returns a 41 point series.
The inverse tangent is defined as:
for all complex z. The function is multi-valued and this definition places the branch cut in the complex plane at
For real x,
-π/2 ≤ atan(x) ≤ π/2
Using atan(imag(x)/real(x)) to calculate the phase angle of a complex scalar or series x will not distinguish between numbers in quadrants I and III, or between numbers in quadrants II and IV. See PHASE
See ATAN2 for a 4 quadrant implementation of the inverse tangent function.
The function calculates in radians unless degrees are specified with the SETDEGREE function.