a. A concave make-up mirror produces a magnification of 2.10 when a person's face is 20cm away. Calculate the focal length, showing your work. b. The person moves closer to a distance 10 cm away from the mirror. Calculate the magnification now.

c. A bi-convex lens of refractive index 1.58, with radius of curvature 45 cm on both sides is used to form an image of an object. Calculate the focal length. d The object is located 40 cm from the vertex of the lens. Calculate where the image by refraction forms, and its magnification. e. Sketch a ray tracing diagram of your solution in part d.