Answer:
c=[tex]\frac{1}{f}[/tex]
Explanation:
using mirror formula
we know
[tex]\frac{1}{u} + \frac{1}{v}=\frac{1}{f}\\[/tex]
where u is object distance
v is image distance
f is focal length of the mirror
from the above equation we can write
[tex]\frac{1}{u}= -\frac{1}{v}+\frac{1}{f}[/tex]
comparing equation with
y= m x + c
c comes out to be [tex]\frac{1}{f}[/tex]