Spherical mirror;find focal length from given data?

[vkash]

Homework Statement

When an object is at distance u₁ and u₂ from pole of concave mirror, images of same size are formed. Find the focal length of the mirror.

Homework Equations

1/v+1/u=1/f

The Attempt at a Solution

Can u please ray diagram for this question. I think their is only one point from which image of size of object form(that's 2f). But it is giving two points. So how to do it..

 

[vela]

I think you're misreading the question. It's not saying the image is the same size as the object. It's saying the image formed when the object is at u₁ is the same size as the image formed when the object is at u₂.

 

[vkash]

I think you're misreading the question. It's not saying the image is the same size as the object. It's saying the image formed when the object is at u₁ is the same size as the image formed when the object is at u₂.

OK!
acha ji.()

but is it possible that two points have same size of image(for a fixed object). I think it will decrease as we take object from pole of the lens to infinity...

please tell me how to proceed..

 

[vela]

Think virtual and real images.