A magnifying glass has a focal length of 8.0 cm. How close to an object do you need to place the magnifying glass so that the distance between the image and the magnifying glass is the same as the focal length? What type of image is this and what is its magnification?
2. Relevant equations
I am thinking that you use the Lens/Mirror equation
1/focal length = 1/object distance + 1/image distance
3. The attempt at a solution
I am unsure of how to do this because I am after object distance. So what I did was 1/object distance = 1/focal length – 1/image distance. But when I do that they just cancel because focal length and image distance are supposed to be the same thing. Once I figure that out I can handle the image type and magnification.