Rahi includes various "math hacks" to help students save time during competitive exams. 3. Clear Language

Use tools like Desmos or the diagrams in Rahi’s book to see what a "limit" actually looks like on a graph.

While a PDF is portable, calculus often requires a lot of "scribbling." Having a physical book allows you to highlight key formulas, dog-ear difficult pages, and solve problems right next to the examples without the eye strain of a screen. Where to Find It