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Math Help - Need Help On A Few Exam Review Problems

  1. #1
    EmG
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    Need Help On A Few Exam Review Problems

    Can anyone help me out on a few or all these problems they are the ones I am cant seem to get. =(
    __________________________________________________

    58. Find a formula for a sum n for the arithmetic sequence.
    a1=-2,d=-6

    59. Find a formula for a sum n for the arithmetic sequence.
    a514,a14=50

    69. Use the Binomial Theorem to expand and simplify the expression.
    (q+5)^5

    70. Find the specified nth term in the expansion of the binomial. (write the expansion in descending powers of x.)
    (3x-2y)^8,n=5

    44. Find gf
    f(x)=x-2,g(x)=x^2

    20. Use Descartes' Rule of Sings to determine the possible number of positive and negative zeros.
    f(x)=5x^5+10x

    13. Find the zeros of the function below algebraically, if any exist.
    f(x)=9x^3-48x^2+64x

    13. Find a third degree polynomial function of the lowest degree that has the zeros below and whose leading coefficient is one.
    2,0,6

    11. Find the zeros of the function below algebraically, if any exist.
    f(x)=x^5-26x^3+25x

    10. Describe the right-hand and the left-hand behavior of the graph.
    u(x)=-2x^4+3x^3+13

    6. Find the value(s) of x for which f(x)=g(x)
    f(x)=x^2+15x-23,g(x)=9x+4
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  2. #2
    Master Of Puppets
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    Hi EmG

    Quote Originally Posted by EmG View Post
    Can anyone help me out on a few or all these problems they are the ones I am cant seem to get. =(
    In future please post 1 question per thread and most importantly with your attempts on the question.


    Quote Originally Posted by EmG View Post
    11. Find the zeros of the function below algebraically, if any exist.
    f(x)=x^5-26x^3+25x
    firstly factor out x from

    f(x)=x^5-26x^3+25x

    to give

    f(x)=x(x^4-26x^2+25)

    now whats left inside can be treated like a quadratic, make the substitution of a = x^2

    f(x)=x(a^2-26a+25)

    f(x)=x(a-25)(a-1)

    f(x)=x(x^2-25)(x^2-1)

    now using difference of 2 squares finally you get

    f(x)=x(x-5)(x+5)(x-1)(x+1)\Rightarrow x=0,1,-1,5,-5

    hope that was easy to understand.
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  3. #3
    EmG
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    Alright will do.
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  4. #4
    Flow Master
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    Please don't post more than two questions in a thread. Otherwise the thread can get convoluted and difficult to follow. Start new threads as necessary for remaining questions. eg. If you have five questions, post two of them in two threads and start a new thread for the remaining one etc.

    And if the question has more than two parts to it, it is best to post only that question and its parts in the thread and start a new thread for other questions.

    Thread closed.
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