12 items are filed under this topic.
 |
|
|
|
|
|
|
|
|
The divisors (aliquot parts) of a positive integer |
2019-10-31 |
|
From Kenneth:
Is there a fast and simple method that can be used to determine the aliquot parts, whole, positive numbers that can divide into another whole, positive number?
Answered by Harley Weston. |
|
|
|
|
|
|
Partitions into distinct parts |
2015-09-19 |
|
From Brian:
Looking for a formula where I can type in a number, 17 for example, and using the numbers 1 through 17 (1, 2, 3, 4 etc....), to come up with all possible combinations, when added, that will equal 17. And each number can only be used once. I've tried a few search engines but my computer stares at me blankly and scratches its head :-/.
Answered by Chris Fisher. |
|
|
|
|
|
|
The integral of sqrt(x) * ln(x) |
2009-10-12 |
|
From Oana:
Hi! Can you tell me please how much is : ∫ (√x * ln x) ?
Answered by Penny Nom. |
|
|
|
|
|
|
Integration |
2008-10-17 |
|
From hazela:
integration of
x sinx cosnx
Answered by Harley Weston. |
|
|
|
|
|
|
Integration by parts |
2008-01-30 |
|
From seth:
hi i really dont understand integr
ation by parts. for example, the integral(t^2sintdt. i have u=t^2 and v'=sint also u'=t^/3 v=-cost
for the formula i have uv-integralvu' dx this is all well and good but i cant get it right.
Answered by Harley Weston. |
|
|
|
|
|
|
Integration |
2007-02-02 |
|
From Jenna:
How do I integrate ( ln(x) ) / ( x^2 ) ?
Answered by Penny Nom and Claude Tardif. |
|
|
|
|
|
|
Can one divide a circle into 4.5 parts |
2006-03-30 |
|
From Chris:
If it is possible, can one divide a circle into say, 4.5 parts (with 4 equal parts and a half part)?
Or for that matter, for any integer, n, into n/2 parts as above?]
Answered by Walter Whiteley. |
|
|
|
|
|
|
Integrating e^x sin(x) |
2003-05-03 |
|
From Lech:
I am having trouble integrating the following expression by parts: ex sin(x) I used the integrator at http://www.integrals.com/ to find the solution, ? 1/2 ex cos(x) + 1/2 ex sin(x). This is easy to confirm by differentiation, however I am confounded as how to arrive at the answer.
Answered by Penny Nom and Claude Tardif. |
|
|
|
|
|
|
Dividing a circle |
2001-10-17 |
|
From Ahmeen:
I am having a hard time figuring out how a circle can be divided into 11 equal parts with only 4 cut allowed? My teacher gave this to us and I still can't cut my pie into eleven equal parts with only four cuts.
Answered by Walter Whiteley. |
|
|
|
|
|
|
Integration by parts |
2001-04-09 |
|
From A student:
how do you integrate x tan-1x dx, i know it can be done by integration by parts maybe, but i'm not sure....
Answered by Claude Tardif and Harley Weston. |
|
|
|
|
|
|
Two integrals |
2001-04-03 |
|
From Jim:
I'm having trouble with these integrals. Can you help me out? 1)the integral of:
x5 arctan x dx 2)the integral of:
2x5 + 9x4 + 19x3 + 13x2 - 5x - 25
----------------------------------------------- dx
x4 + 4x3 + 5x2
Answered by Claude Tardif. |
|
|
|
|
|
|
Congruent parts of congruent figures |
2000-03-10 |
|
From Erica:
Yesterday, I recieved a test problem asking to prove two line segments equal. Here is the problem as I was given it: Given: paralleogram ABCD
AE is perpendicular to DB
CF is perpendicular to DB
Prove: AE is equal to CF I answered the problem as follows:
.
.
.
Answered by Walter Whiteley. |
|
|
