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    I just need help with a simple integration problem: Integrate 1/15*(7-t), where the limits are t and 2. Thank you!

    The answer according to my book is: 1-1/30*(7-t)^(2)

    but I can't seem to get that.
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    (Original post by pprobson92)
    I just need help with a simple integration problem: Integrate 1/15*(7-t), where the limits are t and 2. Thank you!

    The answer according to my book is: 1-1/30*(7-t)^(2)

    but I can't seem to get that.
    the integral of 1/15*(7-t) is 1/15*(7t-t^2/2) = 1/30*(14t-t^2).
    Thus the result is 1/30*(28-4) - 1/30*(14t-t^2) = 1/30*(t^2-14t+24).
    The book's answer is 1/30*(30-(t^2-14t+49)) = 1/30*(-t^2+14t-19), so the book is wrong.
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    I got t^2/30 - 7t/15 + 4/5
    Simplifying to
    t^2 - 14t +24

    Either they cocked up or my maths is terrible
 
 
 
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