GKFix MCQ Question

Why is Eq. (9.21) called the lens maker's formula?

• A. Because it relates the focal length of a lens to the refractive indices and radii of curvature, which is useful for designing lenses
• B. Because it was invented by a person named Lens Maker
• C. Because it only applies to concave lenses
• D. Because it calculates the magnification of images