The calculus courses at MIT are *18.01 Single Variable Calculus* and *18.02 Multivariable Calculus*. Videos of those courses are on OpenCourseWare (OCW) along with lots of other useful materials. This site is about a completely separate calculus textbook by Gilbert Strang, and it will be helpful to viewers of OCW who would like to have online access to a textbook.

Professor Strang’s many contributions to OCW are mostly about linear algebra:

*18.06 Linear Algebra**,**18.065 Matrix Methods in Data Analysis, Signal Processing, and Machine Learning*, and*18.085 Computational Science and Engineering I*

Each of those courses has a full set of video lectures recorded on the MIT campus. Those videos have been watched by millions of viewers around the world (especially *18.06 Linear Algebra*). Calculus and linear algebra are the two principal lead-ins to pure and applied mathematics.

Professor Strang’s *Highlights of Calculus* course on OCW is a series of short videos. They focus on the main idea of the subject, involving two functions: function 2 is the “derivative” of function 1, and function 1 is the “integral” of function 2. If you are given one of those functions, then this calculus textbook and the *Highlights of Calculus* videos show how to derive the other function. The heart of calculus is to use those functions to solve real problems, as described in *Lecture 1: Big Picture of Calculus**.*

Below, Professor Strang shares some thoughts on the history of the calculus textbook:

*For the textbook itself, its first printing was in 1991. That was a time of active “rethinking” of the course. I remember being in the audience at a discussion organized by the US National Science Foundation, about needed changes in typical calculus courses (to make them more relevant and interesting to students). Sitting at the back, I thought one necessary step would be a new textbook. That is the book you see here on OpenCourseWare, published by* *Wellesley-Cambridge Press**.*

*Chapter 0 of the book came in a later edition. Its purposes were to add more figures to illustrate the key ideas of calculus, and also to develop in a new way the most important function in this subject. That function is the exponential* \(e^x\)*. It has a very special feature, because it is both function 1 and function 2! In other words, the derivative of* \(e^x\)*is* \(e^x\)*, and the integral of* \(e^x\)*is* \(e^x\) *(plus any constant C). This becomes the most important function in many applications, including the enormous field of “differential equations” (because it solves the most fundamental differential equation dy/dx = y).*

*I hope the book and the exercises and the videos and even Chapter 0 will be useful to you! Best wishes in all your work.*

*Gilbert Strang*