Solving a problem in physics section 2 point 63 optics

Solving a problem in physics section 2 point 63 optics

63. spire tower building reinforced one under the other two red lights (λ = 640 nm). The distance d between lamps 20 cm. The building is considered a telescope at night from a distance of r = 15 km. Determine the smallest diameter Dmin lens in which its focal plane diffraction images obtained separate.

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Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)