- #1
Ezio3.1415
- 159
- 1
I am having a problem understanding the mathematical reasoning of finding the description of image in convex mirror...
We know the relation,
1/v + 1/u =1/f
is true for all mirrors... we can prove this for both concave and convex mirrors... In case of convex mirrors we use the conventional + and - to get to this general form(I guess real positive system)...
But when they used that formula to find out the position of image they again said for concave mirrors f is minus... I don't understand this point... We derived this formula saying r is minus for concave mirrors... Now what is left is the value... But again why are we saying this is minus?
I tried solving without taking it to be minus but that leads to false answer... Why? Please explain...
We know the relation,
1/v + 1/u =1/f
is true for all mirrors... we can prove this for both concave and convex mirrors... In case of convex mirrors we use the conventional + and - to get to this general form(I guess real positive system)...
But when they used that formula to find out the position of image they again said for concave mirrors f is minus... I don't understand this point... We derived this formula saying r is minus for concave mirrors... Now what is left is the value... But again why are we saying this is minus?
I tried solving without taking it to be minus but that leads to false answer... Why? Please explain...