The focal length of the eye-piece of an astronomical telescope is f1, while the focal length of the object is f2. Fro normal adjustment, the angular magnification is given by
-
\(\frac{f_2}{f_1}\)
- 1 - \(\frac{f_2}{f_1}\)
- \(\frac{f_2}{f_1}\) - 1
- \(\frac{f_1}{f_2}\)