Question

what is the magnification and the image characteristics of a convex mirror that has a radius of 20 cm. An object is placed 30 cm in front of the mirror

Answer 1

$$f=0.5R=10\ cm$$

$$\frac{1}{30}+\frac{1}{q}=-\frac{1}{10}$$

$$q=-7.5\ m$$

$$m=(-1)\frac{-7.5}{30}=0.25$$

Image is virtual, erect and  behind the mirror.