Newest questions posted by Reiny
  1. @ Steve or Damon

    take a look at this question Am I guilty of overkill or over-thinking this ? Surely there has to be an easier way.
  2. Kelly, Justie, Nicole, Keisha

    Please settle on one name
  3. For Hannah

    Re Sorry to have caused confusion for you Hannah. In your original post, you had 3 different problems, the first two were "volume" questions. When I did the third one, which was simply finding an area, I
  4. For Anubhav

    re I have a solution, but what a mess. Before I type it all out, let me know if you still need the solution. I certainly don't feel like typing it all out unless you will actually look at it.
  5. Happy π Day to all mathematicians

    Today, March 14, at 1:59 was a very special time.
  6. Damon or Steve or bobpursley or drwls or ...

    any ideas ? , looks way too messy for here
  7. To Jessica

    I have now corrected two of your replies in which you gave incorrect solutions. Unless you know what you are doing, please don't answer any questions dealing with topics not familiar to you . I know everybody makes mistakes, I make my share, but those are
  8. for Knights

    have been looking at your post ... interesting question... let the altitude of 12 hit base a let the altitude of 14 hit base b then (1/2)(12)a = (1/2)(14)b 6a = 7b a = 7b/6 let the third side be c and its
  9. For MathMate or bobpursley - check this

    Can somebody take a look at this?
  10. For Lia - question from this morning

    I took some time to work out your rather "nasty" Calculus question. Take a look at it and see if it matches your expected result.
  11. MathMate - look at this

    perhaps you can shed some light on this I seem to have a "mental block" here.
  12. For Carry, Alissa,Courtney, Max

    Please do not switch names, it causes unnecessary and duplicate replies from tudors.
  13. Happy Thanksgiving Canada

    Happy Thanksgiving to my fellow Canadian tutors and to the Canadian students at Jiskha.
  14. For Lily

    Please do not append a new question at the end of somebody else posting. Your question will likely be passed over, since most tutors will not look at a posting if they see that it has been answered.
  15. To Math Students, re √ sign

    Several student tonight have asked me how I create the √ symbol to create √ symbol on a PC, hold down the Alt key, and at the same time press 251 on the number pad, then release the Alt key on Mac, hold down the Option key, and press V, release
  16. ATTENTION Ms Sue

    spamming here
  17. Ms Sue -- Welcome back

    hope you had a great trip

    You now have 6 different posts going for the same "cake question" I am not going to keep going back to see which one you replied to. Stay with one posting please. I just notice one way down the list where you did part a) Calculate the area on top of the
  19. For <b>marie flore joseph</b>

    Please do not add your new question as a response to somebody else's post. click on "Post a New Question" above to post your problem. Here is your question : Math - marie flore joseph, Monday, April 5, 2010 at 10:37pm the difference of the squares of two
  20. Happy Pi Day

    Happy Pi Day to all math "nerds" Even Google changed their log today.
  21. Message for KMTRENd

    One would have thought that the least you could have done was give an acknowledgment for a most extraordinary reply you got to your question by tchrwill
  22. To All Students & Tutors

    I will not be able to answer any questions on this board for the next 8 days or so. I will be warming my weary bones down south off one of the islands of Belize for a while. Great time to get away as the temperature up my way is currently at -12 C. Reiny
  23. For Haley

    Even though you mean well, your last three responses have been either incomplete or incorrect. The one to is totally off the mark. Please make sure you are familiar with the topic before replying.
  24. For MUFFY

    You stated on Saturday that you understood my solution as far as part a) and b) were, so let me just recap what we did. (I will not repeat the actual question) My Solution: Suppose we label the point of contact P(x,y). I bet P is in the first quadrant. but
  25. Nice unanswered question by Maggie

    "100 bushels of corn are divided among 100 men, women, and children. Men receive 3 bushels each, women 2 bushels and children 1/2 bushel each. How can the bushels be distributed? is there more than one solution? if so, find the other solutions." let the
  26. Attention : Caroline

    check your post from
  27. All Done

    Ok, logging off, night all.
  28. Message to Students re Math

    Just thought I would let you young'nes know that being a Mathematician has just been chosen as the most rewarding profession. Now I know why I have been so happy all my life, lol So keep
  29. Attention : H Masri

    re your post from late last night
  30. Attention: Courtney's Dad
  31. Reiny to Gina (logic)

    I saw your reply re my late night solution to your pumpkin question I did indeed make two typing errors, which even though they do not change the actual answer, nevertheless would have caused confusion. I
  32. Is Form Going to the dogs?

    sorry, just couldn't resist that.
  33. For George

    At 11:37 and at 12:24 you posted the same question the earlier one was answered correctly by drwls by accepting your question the way you typed it. my solution is based on the assumption that your denominator was e^(t-7), an invalid assumption.
  34. Algebra

    3(2+3-2(4-5)2-1)-3(2+4(4-2)-8+3(2-5)+1-2)1-3)+4-5 rather silly question, and some of it makes no sense eg look at the first part ......-2(4-5)2-1 does this end up -2(-1)(2) ? or did you forget an operator before the last 2? there is a similar discrepancy
  35. math.algebra

    other than factoring out the 9 there is really no simplification that can be made here 9sqrt6 - 9sqrt2 =9(√6 - √2) can someone help me simplify: 9sqrt6 - 9sqrt2
  36. college Algebra

    This is "college" math? Anyway... let the smaller number be x, and the larger number be x+8 then x + x+8 < 12 this is easy to solve, let me know what you got. the sum of two numbers is less than 12. The second number is 8 more than the first.what are
  37. maths

    Set it up this way: Let the number of students be x let the number of rows be y then the number of students per row is x/y This results in 2 equations from your data: (x/y+1)(y-2) = x and (x/y-1)(y+3 = x Solve these two, gets a bit messy at first but it
  38. algebra

    These are very easy to set up with a "chart" ---------Distance-----Rate---Time (D=RxT) slow way --6x----------x-------6 fast way - 5(x+7)-----x+7------5 so 6x = 5(x+7) 6x=5x+35+ x=35 The speed on the slower trip was 35 mph, and on the return trip 42 mph A
  39. math

    break it down into cases at most one day of rain in 3 days to me means we could have: norain norain norain ----> (1/3)^3 = 1/27 rain norain norain -------> 2/3(1/3^2 = 2/27 norain rain norain -------> same as above = 2/27 norain norain rain
  40. I can write it instead

    <Thanks to computers, writing may soon become a lost art.> Leo, a similar prediction is often made about arithmetic since the invention of the calculator. in one of Isaac Asimov writings they discover a man who is actually able to perform an
  41. math

    You did not watch your units, you are mixing inches and feet Your equation should have been 1/2 = 1/di + 1/120 (I changed 10 feet to 120 in) solve this for di and you get 2.03 inches. Please help me I am so confused I think I am losing my mind. The focal
  42. Vectors-another angle confusion

    On an x-y grid, label them N-S, E-W, draw a line from the origin to the right and label it 425 (you are going East) From the end of that line draw a vertical line upwards of 40 (you are going North) Use an approximate scale, realizing that 425 is just
  43. Vectors

    I hope that the diagram I have drawn for myself matches the one in your question. I have a triangle with sides 20 and 10 and an angle of 120º between them By the cosine law I found the third side to be 26.4575. You said you found the maginitude, I hope we
  44. Trig

    I don't know the physics behind Snell's Law, but I can do the math Snell's Law says sin(angle of incidence)/sin(angle of reflection) = refractive index since you know the two angles... sin45/sin27 = refractive index =1.5575365 so for an angle of refection
  45. help, bobpursely

    Please take a look at DEVON's trig equation at 9:14 I must be missing something obvious. If the second had been 3sin 2x it would be a straight forward question. The way it stands I was able to "reduce" it to the equation 8sin^4 x - 8sin^2 x + 3sin x + 2 =
  46. math

    how about (5-3)x2 + 8(5-2) ? To me these are really just "puzzles" and do not actually require much mathematical ability. The best and often only way is to by 'trial and error'. what is the rule when grouping numbers? example I want the answer to be 28. 5
  47. algebra

    I trust you know about y = mx + b Realize that when you are given the x or y intercepts, you are really just given two points, in your case the points (4,0) and (0,-2) So it is easy to find the slope, (-2-0)/(0-4) = 1/2 Take it from there Determine the
  48. algrbra

    Complimentary angles add up to 90º So translate the English into Math. if you let the unknown angle be x then "the measure of the compliment of the angle" -----> 90-x "10 degrees less than three times the measure of the angle" ----> 3x - 10
  49. principles of finances

    according to my interpretation of the question in October they would collect: the 10% of the August sales = .10($10,000) the 20% of the Sept sales = .20($20,000) and the 70% of the Oct sales = .70($30,000) Do the arithmetic and add them up A project has an
  50. calc

    I assume the poster was trying to type "oblique asymptote" from your answer of 3x+2 + 7/(x-1) we can conclude that there is an oblique linear asymptote of y = 3x + 2, and a vertical asymptote at x = 1 for the original function given. how do u find obblique
  51. Monitors of Board

    Is there any way that the postings could be numbered? The post below this one by TONY obviously refers to a previous posting of his 8 steps below. I know the URL has a number behind each particular post, and each post can be identified by a title and
  52. factoring

    let f(m)=m^3 + 3m^2 + 3m + 1 notice f(-1) = 0, so m+1 is a factor. Using division, the answer is m^2 + 2m + 1 which factors once more to (m+1)(m+1) so you have (m+1)^3 = 0 and then m = -1 Are you familiar with Pascal's triangle? Did you notice the pattern
  53. math

    There is no function equation for the Fibonacci numbers, you have to use a Recursion formula. F(n) = F(n-1) + F(n-2) for n>2 and F(1)=1, F(2)=1 what is the equation for the fibonacci sequence