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  1. Use the formula. It's just 'plug and chug'. ...

    Use the formula. It's just 'plug and chug'.

    n=p(1-p)\left(\frac{z}{E}\right)^{2}

    If p is unknown, assume p=0.5

    In this case, E=.015, \;\ z=1.645, \;\ p=.5

    Round up to the nearest whole...
  2. Answers
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    1,735

    Hi Unknown. Long time. :) Linear programming...

    Hi Unknown. Long time. :)

    Linear programming does not require calculus.

    If one graphs the lines generated from the inequalities, one looks at the vertices of their intersections.

    Basic...
  3. Answers
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    449

    You have a typo in your problem. What is 5x-2y...

    You have a typo in your problem.

    What is 5x-2y 1/2z?

    +? -?

    Are you sure that is not z=x^{2}+e^{y}?

    Please make sure the problem is typed exactly as presented.
  4. Answers
    3
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    1,472

    This is a system of two equations with two...

    This is a system of two equations with two unknowns.

    Let m=number of memo pads and let p=number of pens.

    They must make $8400:

    8m+5p=8400

    They want to sell 120 items:
  5. Answers
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    1,035

    This is one solution that works, though it is...

    This is one solution that works, though it is rather abstract. These are the first 5 Euler Phi numbers of the first 5 composite numbers.

    The Euler Phi function or Totient function, \phi(n), is...
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    380

    You are correct. It is indeed 0. It is not an...

    You are correct. It is indeed 0.

    It is not an indeterminate form. It is also continuous.

    Thus, you can do that.
  7. Answers
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    500

    Do a search. Here is a site that may help: ...

    Do a search. Here is a site that may help:

    Behind the Magic Square Maker
  8. Question: Combinations sum

    by galactus
    Answers
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    515

    Look at the sum closely. N is a constant. Say...

    Look at the sum closely. N is a constant.

    Say we have n=10.

    All terms are 0 up to (10-1)C(10,10)=9

    Regardless the value of n, this is true throughout.

    So, the sum is n-1.
  9. Answers
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    530

    1+\frac{cos\theta}{2}-cos\theta is what you have...

    1+\frac{cos\theta}{2}-cos\theta is what you have written.

    And to do what exactly?
  10. Answers
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    3,026

    Jjuiibn;j h hmnk mxvnncvuygaefnbamn I...

    Jjuiibn;j h hmnk mxvnncvuygaefnbamn

    I checked Google and this "problem" has been posted on a dozen different sites. No one else appears to know what it means either.

    Especially, the 3363.
  11. Same concept as with a circle.

    Same concept as with a circle.
  12. Question: 50 letters

    by galactus
    Answers
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    1,103

    This is known as a derangement. The...

    This is known as a derangement.

    The probability that no letter ends up in its envelope is

    \sum_{k=0}^{N}\frac{(-1)^{k}}{k!}

    This is the series for 1/e. So, for large N, the probability...
  13. Answers
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    618

    There is 12.5 grams out of 50 grams remaining...

    There is 12.5 grams out of 50 grams remaining after 14.5 days.

    12.5=50e^{k(14.5)}

    Solve for k.

    Half life is given by:

    T=\frac{-ln(2)}{k}
  14. Answers
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    303

    Since the numbers are consecutive, they can be...

    Since the numbers are consecutive, they can be written as

    x-1, \;\ x, \;\ x+1

    The square of the middle number is x^{2}

    The difference of the squares of the other two:

    (x+1)^{2}-(x-1)^{2}
  15. Answers
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    214

    The margin of error is E=z\cdot...

    The margin of error is E=z\cdot \frac{\sigma}{\sqrt{n}}

    .95 CI corresponds to a z score of 1.96

    So, we have E=1.96\cdot \frac{4}{\sqrt{30}}=1.43

    The CI is then:
    ...
  16. Implicitly differentiate 3x^{2}-y^{2}+xy=4 ...

    Implicitly differentiate

    3x^{2}-y^{2}+xy=4

    to get y'.

    Set the result = to 8/3 and solve for y.
  17. Answers
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    955

    Go here and download the very nice and FREE...

    Go here and download the very nice and FREE graphing utility. Then, graph it.

    Graph

    It looks like an infinity symbol.
  18. Question: Roots problems

    by galactus
    Answers
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    277

    Some explanation from the OP would be nice. But,...

    Some explanation from the OP would be nice. But, I assuming those brackets indicate the floor function.

    If so, then the first one would be x=0,1,4

    I wonder why so many think that those on...
  19. Question: Math Equation

    by galactus
    Answers
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    210

    \frac{5x^{-2}y^{140}}{256x^{-1}(-3x^{-34}y^{-1})^{...

    \frac{5x^{-2}y^{140}}{256x^{-1}(-3x^{-34}y^{-1})^{-67}}

    This is not an equation, it is an expression.

    Equations have equals signs.

    What is it you need to do? Simplify?

    First, write with...
  20. Answers
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    715

    Do you mean 2^{x+2}=4^{-x}? You have...

    Do you mean 2^{x+2}=4^{-x}?

    You have 2^{x}+2=4^{-x} written.
  21. See here as well. ...

    See here as well.
    https://www.askmehelpdesk.com/math-sciences/how-do-you-find-f-f-g-x-if-f-x-2x-5-g-x-square-root-x-568637.html
  22. I will try to decipher. Replace f(x) with...

    I will try to decipher.



    Replace f(x) with y:

    y=k(2+x)

    swap x and y:
  23. Question: Vectors

    by galactus
    Answers
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    498

    A=(0,-1,-1), \;\ B=(4,5,L), \;\ C=(3,9,4), \;\...

    A=(0,-1,-1), \;\ B=(4,5,L), \;\ C=(3,9,4), \;\ D=(-4,4,4)

    AB=-4i-6k+(-L-1)k

    AC=-3i-10j-5k

    AD=4i-5j-5k

    Cross Product:
  24. Sweet. I would give you a greenie, but it won't...

    Sweet. I would give you a greenie, but it won't let me.
  25. Question: Statistic

    by galactus
    Answers
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    1,049

    a. look up the z score corresponding to a .70 in...

    a. look up the z score corresponding to a .70 in the body of the table.

    b. same as above only look up .20

    c. z scores come from the left and go right. So, just look up .75 in the body of the...
  26. Go to a z table and look up .60 in the body of...

    Go to a z table and look up .60 in the body of the table and find its corresponding z score.

    Then, set it equal to the formula z=\frac{x-200}{50}, and solve for x.
  27. Question: Maths - Lim

    by galactus
    Answers
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    2,033

    This post is 3 years old. And you have the nerve...

    This post is 3 years old. And you have the nerve to give me a Not Helpful after posting that nonsense.
  28. Question: Integration

    by galactus
    Answers
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    802

    I assume then that my interpretation was correct....

    I assume then that my interpretation was correct.

    The solution is \frac{2010\pi}{2}=1005\pi

    Try it with other powers of tan. You will see the solution comes out to half of the upper limit of...
  29. 7log(10/9)-2log(25/24)+3log(81/80) Use your...

    7log(10/9)-2log(25/24)+3log(81/80)

    Use your log laws to break it up and simplify in terms of log(2), log(3), log (5). Everything with cancel except for one little ol' log(2).

    For instance, to...
  30. Question: Integration

    by galactus
    Answers
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    802

    Very good JC. I figured this problem had...

    Very good JC. I figured this problem had something to do with observation. This horrific integrals like this normally indicate this. I misread. Either way, good show. Now, let's see if the OP even...
  31. Question: Integration

    by galactus
    Answers
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    802

    Is this what you mean: ...

    Is this what you mean:

    \int_{0}^{2010\pi}\frac{1}{tan^{2011}(x)+1}dx

    If so, may I ask from where you got this crazy integration problem?

    I would venture to say that this is not meant to be...
  32. Answers
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    2,298

    An easy way to find your constant of...

    An easy way to find your constant of proportionately is to use the formula for half-life:

    T=\frac{-ln(2)}{k}

    You are given the half-life decay time. Plug it in and solve for k.

    Then, you can...
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    Look at the factorization for the sum of two...

    Look at the factorization for the sum of two cubes.

    Factor:

    a^{3}+b^{3}

    Let a=sin^{2}(x), \;\ b=cos^{2}(x)
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    I'm sorry, what do you mean "a developer doing...

    I'm sorry, what do you mean "a developer doing some testing"?
  35. Answers
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    1,217

    What you posted is the area of a circle. {\pi}...

    What you posted is the area of a circle.

    {\pi} is the ratio of a circles diameter to its circumference.

    In other words. The distance around a circle is Pi, or about 3.14, times the distance...
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    Part a is obvious. Part b is the same as...

    Part a is obvious.

    Part b is the same as asking if a non-leap year starts on a Sunday. There are 7 days in a week. Wouldn't it be 1/7?
  37. Question: Math

    by galactus
    Answers
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    3,430

    Kudoes, JCaron. I couldn't agree more. I...

    Kudoes, JCaron. I couldn't agree more.

    I tried giving you a rep, but it will not let me. Some silliness about "spreading it around". I don't know how to take that:)
  38. Answers
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    432

    Assuming the keys are identical and the boxes are...

    Assuming the keys are identical and the boxes are different.

    If we are distributing r identical objects into n different boxes, then there are

    C(r+n-1,r) ways

    In this case, C(5+3-1,5)=21...
  39. If repetition is allowed, then there are ...

    If repetition is allowed, then there are

    6^{3}=216 numbers that can be formed.

    If repetition is not allowed, then there are

    6\cdot 5\cdot 4=120 numbers that can be formed.

    When forming 3...
  40. Answers
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    Assuming they are well-defined, the inverse would...

    Assuming they are well-defined, the inverse would be

    g^{-1}of^{-1}
  41. Here is what you have written: ...

    Here is what you have written:

    x^{2}+7x+\frac{12}{x^{3}}+4x^{2}-x-4

    I assume you mean:

    \frac{x^{2}+7x+12}{x^{3}+4x^{2}-x-4}

    This is why grouping symbols are important.
  42. Answers
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    319

    But, if you want to do this algebraically, let''s...

    But, if you want to do this algebraically, let''s do this:

    Take log of both sides:

    log(x^{log(x)-1})=2

    (log(x)-1)log(x)=2

    (log(x))^{2}-log(x)-2=0
  43. Answers
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    Yep. That's them. Good :)

    Yep. That's them. Good :)
  44. Answers
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    319

    Is this what you mean?: x^{log(x)-1}=100 If...

    Is this what you mean?:

    x^{log(x)-1}=100

    If so, look close. There are two solutions.One is rather obvious.

    What is log(100)? Isn't it equal to 2?

    So,...
  45. I assume y is the number of kg produced or sold....

    I assume y is the number of kg produced or sold.

    Thus, R=160y

    Remember, P=R-C

    Profit=Revenue-Cost
  46. When a tie happens at least one basic variable...

    When a tie happens at least one basic variable will be zero in

    the next iteration and the new solution is called 'degenerate'.

    Say we wanted to maximize z=3x_{1}+9x_{2}

    s.t. ...
  47. Question: Law of exponents

    by galactus
    Answers
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    227

    Exponent? What exponent? Solve what? Rewrite...

    Exponent? What exponent? Solve what?

    Rewrite 5 and 3/4 as a decimal? 5.75
  48. Question: 2x=4

    by galactus
    Answers
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    2,431

    No one is that stupid, so it makes me believe...

    No one is that stupid, so it makes me believe this is just a troll with nothing better to do.
  49. Answers
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    1,328

    I assume this is what you're describing?: The...

    I assume this is what you're describing?:

    The section 1/8th inch on either side of the x-axis must be the same as the segment with height h?

    Assuming I am interpreting correctly, find the...
  50. Question: Log8 1=x

    by galactus
    Answers
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    1,906

    log_{8}(1)=x To write it another way: ...

    log_{8}(1)=x

    To write it another way:

    8^{x}=1

    What must x be?
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