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 Let us recall that if y = sin–1x, then x = sin y and if x = sin y, then y = sin–1x