Question

Sign convention of mirror and lens​

Answer 1

Answer:

on going left-side of pole of mirror/lens distance is taken as negative and on going right side of mirror/lens distance is taken as positive.

similarly if image or object is inverted height is taken as negative and if it is erect height is taken as positive

Answer 2

Answer:

object is always placed in front of the mirror hence the sign of object is taken as negative.