Question

the magnification product of a mirror is +1 . what does it mean ?

Answer 1

The magnification product of a mirror is +1 
it means that

1) the image will have same size of that of the object
2) it will be formed on the same side where the object is placed
3)the mirror can be a plane mirror
4)the object may be placed at the centre of curvature

Answer 2

The magnification produced by a plane mirror is +1 implies that the image formed by a plane mirror is virtual , erect and of the same size, as that of object.