asec

Arguments

x

a real or complex array.

y

a real or complex array.

Description

Computes the element-wise inverse secant of the argument. For real argument with absolute value greater than 1 the result is real.

The following equalities hold: asec(z) == -acsc(-z) == asin(1/z) == %pi/2-asec(x) == %i*acsch(%i*z).

Sample

Examples

x=[1 2 -2 sqrt(2) -sqrt(2) 2/sqrt(3) -2/sqrt(3) -1];
asec(x)/%pi

See also

• sec — computes the element-wise secant of the argument
• asecd — computes the element-wise inverse secant of the argument, results in degree.

References

• Kahan, W., "Branch cuts for complex elementary functions, or, Much ado about nothing's sign bit", Proceedings of the joing IMA/SIAM conference on The State of the Art in Numerical Analysis, University of Birmingham, A. Iserles and M.J.D. Powell, eds, Clarendon Press, Oxford, 1987, 165-210.