In a concave mirror if x1 and x2 are the distances of object and its image respectively from the focus, then the focal length of the mirror is -

In a concave mirror if x1 and x2 are the distances of object and its i

1.	In a concave mirror if x1 and x2 are the distances of object and its image respectively from the focus, then the focal length of the mirror is -
A.	x1x2
B.	\(\frac{(x_1+x_2)}{2}\)
C.	\(\sqrt{x_1x_2}\)
D.	\(\frac{x_1x_2}{x_1+x_2}\)
Answer» D. \(\frac{x_1x_2}{x_1+x_2}\)

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In a concave mirror if x1 and x2 are the distances of object and its image respectively from the focus, then the focal length of the mirror is -

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