New SIDBI Grade A New Batch Starts on Nov 18

    Register

    Question

    B1 is a point on the side AC of ∆ ABC and B1B is joined. line is drawn through A parallel to B1B meeting BC at A1 and another line is drawn through C parallel to B1B meeting AB produced at C1. Then

    A 1/CC1 – 1/AA1 = 1/BB1 Correct Answer Incorrect Answer
    B 1/CC1 + 1/AA1 = 1/BB1 Correct Answer Incorrect Answer
    C 1/BB1 – 1/AA1 = 1/CC1 Correct Answer Incorrect Answer
    D 1/AA1 – 1/CC1 = 1/BB1 Correct Answer Incorrect Answer

    Solution

    ∆AA1C & ∆BB1C AA1 ‖ BB1 (BB1) / (AA1) = (B1C) / (AC) By ratio of Similarity in ∆ACC1 ~ ∆ABB1 = BB1 ‖ CC1 = (BB1) / (CC1) = (AB1) / (AC) = (BB1) / (CC1) = (AC – B1C) / (AC) = (BB1) / (CC1) = 1 – ((B1C) / (AC) from (1) (BB1) / (CC1) = 1 – (BB1) / (AA1) BB1[1/CC1 + 1 / AA1] = 1 = (1 / CC1) + (1 / AA1) = (1 / BB1)

    Practice Next

    Relevant for Exams: