When students ask for a "verified" PDF, they usually mean one that meets three criteria:

Some academic institutions, such as Mohanlal Sukhadia University , provide authorized e-content or partial chapters for their students.

Despite the rise of interactive simulations and YouTube tutorials, A Textbook of Optics remains a staple. Its structured approach builds a foundation that helps students tackle competitive exams like GATE, NET, and JAM.

Your best bet is:

: Derive the laws of reflection and refraction using the principle of least time.