If you rely solely on a PDF textbook, you will likely understand the concepts but run out of time on exam day. Use your digital textbook to learn why the quadratic formula works, but use printed past paper booklets (or timed digital mock exams) to learn how fast you can use it.
Standard textbooks give you standard answers. To get a 5**, you need to write examiner-pleasing steps. Search for "DSE Maths 5** Solution PDF." These are often compiled by top-scoring alumni and show you how to skip steps while still earning full marks. dse math textbook pdf