A convergent lens of 6 diopters is combined with a diverging lens of -2 diopters. Find the power of combination?

4 diopter 6 diopter 8 diopter 10 diopter

4 diopter

Here $P_1$ = 6 diopters, $P_2$ = -2 diopters Using the formula $P = P_1 + P_2 = 6 – 2 = 4$ diopters