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  1. A

    where did this term go?

    I was looking a method for deriving the quadratic formula from the form:ax^2+bx+c=0 but got taken up short when I couldn't account for the whereabouts of a term. Here is the book's presentation: Now, what is puzzling me is this: Where does the b/a times x go after the 4th equals sign? I mean...
  2. A

    where does this (1/2) come from

    well, I didn't really think the book was wrong. But I just couldn't figure out how it was right. If I had the brains I was born with I would have checked the problem again.
  3. A

    where does this (1/2) come from

    yep, you got it. I should read things more closely. Here is the problem:
  4. A

    where does this (1/2) come from

    what you say is probably right. I don't have access to the book right now so I have to wait til tomorrow to check it. The problem has to do with finding the total volume of a cylinder with a cone on the end of it that is being used as a hopper to fill grain trucks, if I am correctly remembering...
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    where does this (1/2) come from

    The following is from a precalculus text I am studying by Earl Swokowski. The cylinder being referenced has a radius of 2 in. First he gives the formulas for volume of a cylinder and for volume of a cone and right after each formula he gives what we get when we are working with a cylinder and...
  6. A

    Is this right?

    I agree. I will try to make things neater. As for what I posted in that photo...I think knew what I wanted to present when I presented it...but only God knows now.
  7. A

    Is this right?

    good old Arky!
  8. A

    Is this right?

    too old for that to be interesting for either myself or anyone else.
  9. A

    Is this right?

    yes, I knew the author was factoring but I discovered today that I was misunderstanding a very crucial step--when the one factor was taken (whole) from the right side of the sum I kept missing the point that there was a one left in its place. The one then disappeared because it was a factor of...
  10. A

    Is this right?

    well, my problem centered around not being able to see how he could take two terms from different sides of the plus sign and then use them as multiplier for a binomial on the other side of the plus sign and still get the result he gets. I spent a long time going through this process and tried to...
  11. A

    Is this right?

    You are right. I will supply the whole problem now. I posted the above just after I had gotten done working on this problem and really didn't know what I was doing. I thought the work above meant something but when I look at it now I can't remember what. Here is the whol;e problem worked out in...
  12. A

    Is this right?

    This is part of a problem that I have been breaking my head against for 2 hours today. Please tell me if the following is correct and if not, why not:
  13. A

    this stumps me:

    I don't see what you mean here. I do have a negative sign--although I admit it is not very easy to make out--with (-r+4).
  14. A

    this stumps me:

    I went at this again today and here is what I got. It is not quite what the other posters have...but I think that is attributable to some kind of synonomy? Or have I made some kind of mistake? I have 1/R instead of -R/R2 because -R divided by R2 is -1. No?
  15. A

    this stumps me:

    Right. I see it now. Thanks
  16. A

    this stumps me:

    I see it now but somehow the fact that this is a quadratic expression was completely lost on me. No way to excuse this...I have seen plenty like this with constant out front, but somehow I missed this one. Thanks for replying
  17. A

    this stumps me:

    Oh boy! I misread the thing...somehow I missed the fact that the numerator is a quadratic expression. What a dope! Thanks for pointing this out. Sometimes it happens...the answer is right there hanging out for all the world to see and...I don't see it. At least I did factor the denominator.
  18. A

    this stumps me:

    I came across this problem at the end of one section of the algebra review in my precalculus. I will post the problem and how I tried to work it out--it has been asked of us to simplify the expression: Problem: Here is how I tried to simplify this: Here is what I got from my calculator: I...
  19. A

    what does this notation mean? "Verify (bar over)(z + w) = (bar over)(z) + (bar over)(w)" What are the bars?

    No. I did not notice the overhead line. Again. You are right. The second term is the conjugate. Thanks for pointing that out. Yes, I can see the tautology. I have been just dumb2 working with this problem. But slowly I am getting it. Part of the trouble is I have not had much exposure to the...
  20. A

    what does this notation mean? "Verify (bar over)(z + w) = (bar over)(z) + (bar over)(w)" What are the bars?

    here is my problem: When I multiply (a+bi)(a+bi) I get (a^+2bi-b^2). I don't see how you can say multiplying the first two terms = (a+bi)(a-bi).
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