It may be mentioned here that these results are valid within the principal
value branches of the corresponding inverse trigonometric functions and wherever
they are defined Some results may not be valid for all values of the domains of inverse
trigonometric functions In fact, they will be valid only for some values of x for which
inverse trigonometric functions are defined We will not go into the details of these
values of x in the domain as this discussion goes beyond the scope of this textbook