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Forum: General Questions - High School/Secondary
Welcome to the General Questions - High School/Secondary forum!
For discussing questions from any discipline at high school/secondary school level.

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Calculating the Point where a radian intersects a circle by SoggyB on 2008-06-16 18:36:41
Let's see if I can use the right terms to ask the question...

If you have a x/y grid, and you place a circle on that grid at a known point(x,y), given the radius of the circle, how do you calculate the point(x,y) where a radian or angle from the center of the circle meets the edge of the circle?

Am I using the right terms?

Thanks
[ reply | up ]
center of gravity by curious on 2008-05-30 16:00:59
I know the center of gravity of a uniform cicular sector is d = (2r sin x)/(3x), where d is the distance from the center and x is half the central angle of the sector. Can someone prove it or anyone has a link for the proof?
I tried to use the 2 theorems of Pappus, but I couldn't reach an answer. Any idea?
[ reply | up ]
Limits by senojr on 2008-05-23 15:03:34
If F(x) and G(x) are continuous for all x and both are unlimited;
does the limit [G(x)/F(x)] exist?

Bill J
[ reply | up ]
  • Re: Limits by azdbacks4234 on 2008-05-23 15:35:56
fibonacci puzzle by curious on 2008-05-12 16:17:27
Can someone give me an exapmle of a fibonacci puzzle with its solution?? I saw on the internet few of them about areas, but none of them had any solutions.
Example:
Draw an 8 by 8 square and subdivide it into four pieces (in a certain way which I cant draw here). This square has area 64. If you rearrange the four pieces you can build a rectangle whose sides are 13 and 5. This rectangle has area 65. Where did we gain an extra square? That is, how did we gain more area simply by rearranging the pieces?

Thanks
[ reply | up ]
solve integrals using complex no.s by curious on 2008-05-05 16:49:45
i read in a book that we can solve some integrals more easily if we complexify the integrand. So for example, integral cos (x)*e^(-x) dx can be easily solved if we think of it as a complex function e^(-x+ix), take x common factor and integrate simply, then take the real part of the answer.
But i tried using this technique on integrals such as integral 1/sin(x) dx, or integral 1/cos(x) dx, and i got a wrong answer!!
Does any one know why?? And please tell me about the details of this technique and when and how to use it because i dont really get it.

Thanks
[ reply | up ]

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