Differential Equations - Linear Theory and Applications (DELTA) is an e-book based on my teaching of Math2930 Differential Equations and Math2940 Linear Algebra at Cornell. It is in two Parts - the first Part is on Ordinary Differential Equations and the second Part is on Partial Differential Equations. This second Part, I believe, represents an approach different from the standard texts and is a useful resource for students of physics and engineering.

From the back of the book : Differential Equations – Linear Theory and Applications (DELTA) is a text cum problem collection on ordinary and partial differential equations. For each topic, a succinct exposition of the theory is followed by a series of problems, ranging from simple to difficult, and dealing with real-world phenomena taken from classical mechanics and vibrations, elasticity theory, electromagnetism and electrical engineering, quantum mechanics, and acoustics.

Some of the problems have been published in pedagogical and research journals (just to clarify, I myself am the author). For example, Tutorial 125 has been published in AIP Chaos, Tutorial 68 in European Journal of Physics and Tutorial 129 in Physics Letters A.

DELTA now has bookmarks !! Please use the bookmarks for navigation. The e-file is optimized for two-page viewing - a left hand page of the print version appears as left hand page here and the same holds true for the right hand pages. The file size is 15.5 metric megabytes or 14.7 long megabytes.

Every few weeks I shall be uploading a new version of DELTA. The continuous updation reflects the feedbacks which I obtain from readers and addresses the issues which I myself detect with the existing edition. So even if you have downloaded a version, please check back regularly for updates. The good news is that DELTA won't keep on getting longer with each update. The Tutorial counts of the two Parts (75 in Part 1 and 55 in Part 2) are constrained to remain constant so that alone prevents an unbounded growth of the length. The current edition is

I just noticed that the link to the video in Tutorial 068 does not work. Please either copy and paste the address in your browser or view the video here. I shall correct this deficiency in the next updation.

I wholeheartedly welcome your comments, criticisms, suggestions for improvement and any other feedback. I will be updating the version periodically, correcting errors as they are found.

DELTA is perfectly free to download, distribute and read. However, if you use any result contained here in your paper, book or other academic publication, please cite DELTA. The citation reads as :

Please also mention the number of the relevant Unit or Tutorial, if appropriate.