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    Value of A for the equation: tan A + tan 2A+ tan 3A = tan A tan 2A tan 3A is
    Question

    Value of A for the equation:
    tan A + tan 2A+ tan 3A = tan A tan 2A tan 3A is

    A.

    5π/6

    B.

    π/3, 2π/3

    C.

    2π/3 only

    D.

    π/3 only

    Correct option is B

    Given:

    tan A + tan 2A + tan 3A = tan A tan 2A tan 3A

    Solution:

    tan A + tan 2A + tan 3A = tan A tan 2A tan 3A

    => tan A + tan 2A = -tan 3A + tan A tan 2A tan 3A 

    => tan A + tan 2A = -tan 3A (1 –  tan A tan 2A)

    => (tan A + tan 2A)/(1 –  tan A tan 2A) = -tan 3A

    => tan (A + 2A) = -tan 3A

    => tan 3A = -tan 3A

    => 2 tan 3A = 0

    => tan 3A = 0

    ​=> A = nπ/3​

    put n=1 then value of A =π/3​

    put n=2 then value of A=2π/3

    put n=3 then value of A=π

    So, according to question values of A are π/3,2π/3 .

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