Many students after reading the question take a long time to begin as they don't know how to start. The trick is to draw! Drawing helps us to see and understand the question better.
Drawing is one of the keys to answer this question. To answer part (a), we need to notice the property of radius is perpendicular to tangent. Also, in part (b) of the question, we need to apply discriminant from the topic of Quadratic.
I have shared my thinking process and step-by-step solutions in the following videos.
How did you find the videos? Did they help you to understand better? Leave me your feedback in the comment section.
Part (a) URL: Click here to watch part (a) 7 minutes
Part (b) & (c) URL: Click here to watch part (b) & (c) 5 minutes.