Question

    If (a - b - c) = 6, and (ab - bc + ca) = 117, then find

    the value of (a 2  + b 2  + c 2 )
    A 270 Correct Answer Incorrect Answer
    B 332 Correct Answer Incorrect Answer
    C 296 Correct Answer Incorrect Answer
    D 286 Correct Answer Incorrect Answer

    Solution

    We know that, (a - b - c) 2  = a 2  + b 2  + c 2  - 2(ab - bc + ca)

    Or, 36 = a 2  + b 2  + c 2  - 2 X (117)

    Or, a 2  + b 2  + c 2  = 36 + 234 = 270

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