Two thin convex lenses (1 and 2) and a small object are arranged as shown.
a) Use the three principal rays to determine the location of the image of the object produced by lens 1.
b) Treat the image produced by lens 1 as an object for lens 2. Use the thee principal rays to determine the location of the image of this produced by lens 2.
Is this image produced by the pair of lenses real or virtual? Explain your reasoning.