posted by Determine the radius .
An object that is 19 cm in front of a convex mirror has an image located 24 cm behind the mirror. How far behind the mirror is the image located when the object is 12 cm in front of the mirror?
I found that 1/Di = 1/-24 + 1/19 - 1/12 = -.07236.
And that means that f= -13.82. But I am being told that this is wrong. Can you please help??
The answer should be positive, so 13.82 is correct