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Myvy121
2 năm trước
Các anh não to ơi, giúp em với ạ :<< please Cho vật sáng AB có dạng đoạn thẳng và 1 thấu kính hội tụ có tiêu cự f=20cm. 1.Đặt vật AB vuông góc với trục chính của thấu kính, A nằm trên trục chính và nằm khoảng ngoài tiêu cự. Vật AB cho ảnh A'B' qua thấu kính. ->Vẽ hình. (cái này em làm dc rùi ạ :v) ->Chứng minh biểu thức: AF.A'F'=OF.OF' với F,F' là các tiêu điểm của thấu kính.
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