## Fundamentals of Physics Extended (10th Edition)

The image distance is given by $i = -mp = -(-1/2)(60) = 30 cm$ By substituting i = +30 cm and p = +60 cm into the focal length equation, we obtain: $1/f = 1/p + 1/i = 1/60 + 1/30\\\\ f = +20 cm$