When do you use notation arctan

Conway, J. New York: Springer-Verlag, pp. GNU C Library. Gosper, R. Gradshteyn, I. Tables of Integrals, Series, and Products, 6th ed. Harris, J. Handbook of Mathematics and Computational Science. Hildebrand, J. Jeffrey, A. Orlando, FL: Academic Press, pp. Lagrange, J. Reprinted in Oeuvres, Vol. Lambert, J. Theil 2. Berlin, Lehmer, D. Monthly 45 , , Olds, C. Continued Fractions. New York: Random House, Salamin, G.

Item in Beeler, M. Sloane, N. Spanier, J. Save my name, email, and website in this browser for the next time I comment. Skip to content Trigonometry 0. Select your language English Spanish. Leave a Reply Cancel reply Your email address will not be published. In the plot below, atan only gives back results in the right half of the circle. This is why, there is also a four-quadrant inverse tangent, atan2 y,x. Note this version of the inverse tangent requires two input values.

For more information on the math behind arctan, click here , or for arctan2, click here. The set of all functions or, if you prefer, all functions defined on a specific interval is not just a set of individual things, like buttons on a calculator; there are relationships among them, and operations that can be performed on them.

Let's consider how we answer these questions for the three operations I've mentioned: addition, multiplication, and composition. Now what about additive inverses? Now what about multiplicative inverses? We need both requirements here because composition, unlike multiplication and addition, is not commutative.

People usually just call it the "identity function", and drop the word "compositional", but I'm going to keep it here because the distinction between function multiplication and function composition is at the core of your question. Now what about compositional inverses?

Notice what has happened: for each operation, there is an identity function, and a different kind of inverse function. Let's take a specific example, related to the one you asked about. Confusion between the two operations of "function multiplication" and "function composition" is commonplace and, to some extent, natural. Sign up to join this community. The best answers are voted up and rise to the top.

Stack Overflow for Teams — Collaborate and share knowledge with a private group.