17

arccos(z)

Show
3-d plot

Inverse trigonometric functions:

The function arccos(z) is the inverse cosine. If z = cos(w), then w = arccos(z). The inverse cosine is multivalued. The principal part shown in the image is obtained by restricting the argument of z to the interval [-Pi, Pi]. This function is zero at z=1 and has branch lines extending from +1 and -1 to infinity along the real axis.