where should an object from a convex mirror of focal lenght 20cm be held so as to obtain an erect, d

given: f =  20 cm; m = 1/ 2

since m = - v / u

v = -  u / 2

using (1 / f) = (1 / v) + (1 / u)

(1 / 20) = ( 2 / - u) + (1 / u) = -1 / u

object distance = - 20 cm

Due to some technical problem, ray diagram can not be uploaded.