The lens maker equation:

$\overline{)\frac{\mathbf{1}}{{\mathbf{s}}_{\mathbf{o}}}{\mathbf{+}}\frac{\mathbf{1}}{{\mathbf{s}}_{\mathbf{i}}}{\mathbf{=}}\frac{\mathbf{1}}{\mathbf{f}}}$

Considering distances on the lens to be negative:

s_{o} = - s_{o} and s_{i} = s_{i}

1/f =1/s_{i} - 1/s_{o}

A lens creates an image as shown. In this situation, the object distance *s* is

a) Larger than the focal length *f*. ?

b) Smaller than focal length *f*. ?

c) Equal to the focal length *f*. ?