A concave mirror forms a real image of an object kept at a distance 9 cm from it. If the object is taken away from the mirror by 6 cm, the image size reduces to <img alt="\frac{1}{4}^{th}" src="https://learn.careers360.com/latex-image/?%5Cfrac%7B1%7D%7
A concave mirror forms a real image of an object kept at a distance 9 cm from it. If the object is taken away from the mirror by 6 cm, the image size reduces to of its previous size. Find the focal length of the mirror.