A convex lens of focal length f1 and a concave lens of focal length f2 are placed in contact. The focal length of the combination is_____________?A. f2 + f1B. f2 – f1C. f1f2/f2+f1D. f1f2/f1-f2 0 0 votesArticle Rating Subscribe LoginNotify of new follow-up commentsnew replies to my comments Label {} [+] Name* Email* Website Label {} [+] Name* Email* Website 0 Comments Oldest Newest Most Voted Inline FeedbacksView all comments