equations for lense

Question 1

Equation for lenses signs

Answer 1

Distances of real objects and images are positive

Distances of virutal objects and images are negative.

heighs of uprigths object are postive

heights of inverted object are negtive

Question 2

Converging lens

Answer 2

has a postive focal length

Question 3

A diverging lens has a

Answer 3

negtive focal length