An object in front of a concave mirror has a virtual image that is 16.5 cm from the mirror. The mirror's radius of curvature is 19.5 cm. (Include the sign of the value in your answers.)

(a) What is the object distance?
(b) What is the magnification?

1 answer

What I find comfusing on these is to remember the sign conventions. What worked for me is to sketch a ray diagram first, get an order of magnitude answer from the ray diagram, then do the math to check signs.