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Arc length |
2002-04-17 |
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From Vix:
Find the point on the curve r(t)=(12sint)i-(12cost)j+5tk at a distance 13pi units along the curve from the point (0,-12,0) when t=0 in the direction opposite to the direction of increasing arc length.
Answered by Harley Weston. |
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Ratios |
2002-04-17 |
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From A student:
- Medication is givin at 1cc. per 20 pounds of body weight. A dog weighs 16 pounds how many ccs. of medication does the dog get?
- Dr. Lee wants you to prepare 1000 ml. of a 10% dextrose solution in lactaed ringers for diuresis or a patient you have a 1 L bag of lactated ringers and 500 ml of 50% dextrose for injection. How would you prpare the solution?
Answered by Penny Nom. |
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Related rates |
2002-04-17 |
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From Molly:
A tanker spilled 30 ft cubed of chemicals into a river, causing a circular slick whose area is expanding while its thickness is decreasing. If the radius of the slick expands at the rate of 1 foot per hour, how fast is them thickness of the slick decreasing when the area is 100 feet squared?
Answered by Penny Nom. |
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Un empilement de spheres |
2002-04-16 |
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From Sébastien:
Lorsque j'etais encore a l'universite je me souviens qu'un prof nous avez dit, sans le demontrer (ce n'est pas bien du tout de sa part) que l'espace minimal qui existe dans un empilement de spheres est de l'ordre de 26% Voici plusieurs jours que je cherche a resoudre ce probleme de geometrie, et je n'arrive meme pas a trouver comment l'aborder.
Answered by Claude Tardif. |
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Two algebra problems |
2002-04-14 |
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From Ashley:
Question 1: For all values of a, let < a > be defined as < a > = 4a - 4 . Which of the following equals < 6 > - < 5 >? A: < 2 >
B: < 3 >
C: < 4 >
D: < 5 >
E: < 6 >
Question 2: If 5n + p = 3 and 2m - 10n = 2, what is the value of m + p?
Answered by Penny Nom. |
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A polynomial |
2002-04-14 |
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From A student:
A polynomial function is described by the following conditions: f(x) has two real zeros at x= -2 and x= 1, each of multiplicity 2 f(x) has two complex zeros as x goes to -infinity, f(x) goes to +infinity as x goes to +infinity, f(x) goes to +infinity f(x) has a y-intercept at (0,2) Sketch a polynomial function that satisfies the above conditions. Write an equation for function f(x) Write another function g(x) that also satisfies the above parameters.
Answered by Penny Nom. |
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How many gallons of water in a cubic foot? |
2002-04-14 |
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From Richard:
I am tring to find out how many gallons of water in a cubic foot.
Answered by Penny Nom. |
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The vertex of a cone |
2002-04-13 |
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From Callie:
Does a cone have a vertex?
Answered by Penny Nom. |
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The square root of four |
2002-04-13 |
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From Frank:
In a recent quiz we where asked the square root of four. The quizmaster gave the answer as not only 2 but also -2. Being pedantic I queried this. Although -2 squared is 4, does it follow that the root of 4 is -2 Can you enlighten us?
Answered by Claude Tardif and Penny Nom. |
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The bleep test |
2002-04-13 |
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From Lorraine:
I am currently undergoing training and have asked about a fitness test called the bleep test. The bleep test involves running continuously between two points that are 20m apart. These runs are done in time to a pre-recorded bleep sounds on a pre-recorded audio cassette. The time between the recorded bleeps decrease after each minute. I would like to do my own personal version for training but I have to work out the following before doing this: I need to find out the time in-between the beeps at least for the first level so I can work out the difference for the other levels: The information given to me for the first level is : A 20 meter run at 8.5km/hr (how long would it take?) Please let me know if there is any way in working out this query with the information given.
Answered by Leeanne Boehm. |
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Calculate profit |
2002-04-13 |
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From Allison:
If I sell something for $75; and my cost is $40, I make $35 profit. How do I calculate the profit percent I made on that transaction?
Answered by Penny Nom. |
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Nombres algebriques sur Q |
2002-04-11 |
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From Un eleve:
On sait que le corps des nombres algebriques sur Q est algebriquement clos. A priori partant d'un polynome f a coefficients algebriques sur Q on devrait pouvoir un trouver un polynome g a coefficients rationnels dont une partie des racines est constituee de racines du premier. y-at-il un algorithme qui permet qui permet le passage de f a g ?
Answered by Claude Tardif. |
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Problème de traduction |
2002-04-11 |
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From Philippe:
Je suis professeur de mathématiques en collège et j'aimerai que la classe de 5ème, qui a une spécialité "Anglais", fasse un cours de mathématiques en anglais. N'étant pas moi même trés fort en mathématiques version anglaises, je vous sollicite donc pour répondre à certaines de mes questions. Par exemple, je me demande comment on dit " 3 fois 5" en anglais. "2 plus 2" se dit "2 and 2 is...". J'ai des problèmes avec la multiplication, la soustraction (" minus" ou "out of" ?), et la division. De même , comment dit-on "2/3". J'ai aussi des problèmes pour le vocabulaire mais je pense pouvoir le résoudre en utilisant un bon dictionnaire. Ma question est donc: Existe-t-il des sites qui propose ce genre de traduction?
Answered by Claude Tardif. |
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Diagonals in a polygon |
2002-04-10 |
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From Murray:
If you have a regular polygon with n sides and you draw all (n-3)n/2 diagonals how many intersection will they form with each other and how many sections will they devide the polygon into.
Answered by Caude Tardif and Chris Fisher. |
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n +1, n+2, n+3, and n+4 are all composite |
2002-04-09 |
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From Jonathan:
Find the small integer n such that n +1, n+2, n+3, and n+4 are all composite
Answered by Penny Nom. |
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