Formulas areYou wish to form an image of the moon, diameter 3500 km, a distance of 380 000 km away, with a reflecting telescope. If the image needs to be 4.5 cm in diameter, find the required focal length of the mirror in the telescope.

F stands for focal point, di is distance to the image, do is distance to the object, hi is height of the image and ho is height of the object.

is this correct???