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March 28, 2017

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write the sigma notation.

5^2+6^2+7^2+...+14^2

You could use capatil E as a sigma.

Please help!!

  • calculus - ,

    5 = 1 + 4

    6 = 2 + 4

    7 = 3 + 4
    ...

    14 = 10 + 4


    5 ^ 2 + 6 ^ 2 + 7 ^ 2 + ... + 14 ^ 2 =

    ( 1 + 4 ) ^ 2 + ( 2 + 4 ) ^ 2 + ( 3 + 4 ) ^ 2 + ... + ( 10 + 4 )^ 2 =

    E ( k + 4 ) ^ 2 from n = 1 to n = 10

    ________________________________________


    ( k + 4 ) ^ 2 = k ^ + 2 * k * 4 + 4 ^ 2 =

    k ^ 2 + 8 k + 16

    _______________________________________


    E ( k + 4 ) ^ 2 from n = 1 to n = 10 =

    E k ^ 2 from n = 1 to n = 10 + 8 * E k from n = 1 to n = 10 + E 16 from n = 1 to n = 10 =

    E k ^ 2 from n = 1 to n = 10 + 8 * E k from n = 1 to n = 10 + 10 * 16 =

    E k ^ 2 from n = 1 to n = 10 + 8 * E k from n = 1 to n = 10 + 160

    ________________________________________

    E k ^ 2 from n = 1 to n = 10

    = n * ( n + 1 ) * ( 2 n + 1 ) / 6 =

    10 * ( 10 + 1 ) * ( 2 * 10 + 1 ) / 6 =

    10 * 11 * 21 / 6 = 2310 / 6 = 385

    _______________________________________

    E k from n = 1 to n = 10

    = n * ( n + 1 ) / 2 = 10 * 11 / 2 = 110 / 2 = 55

    _______________________________________


    E ( k + 4 ) ^ 2 from n = 1 to n = 10

    = E k ^ 2 from n = 1 to n = 10 + 8 * E k from n = 1 to n = 10 + 160

    = 385 + 8 * 55 + 160 = 385 + 440 + 160 = 985

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