# Recent content by MathStudent

1. ### Quick counting question

I'm on the verge of a solution but the computer lab is closing so I'll have to wait till tomorrow to post :frown:, sorry. Hopefully someone else will help out till then. They must mean arrangements of all possible sizes, since the total number of arrangements of size 25 is much much less...
2. ### Quick counting question

are arrangements of any size allowable? ie: 1 ball, 2ball, .... arrangements, or do they have to be a fixed size?
3. ### Question on Electricity

I'm not sure I'm the best person to answer this question, hopefully someone with more knowledge will come in and offer a more detailed answer, but for the mean time, The charges that develop from the glass/silk & plastic/fur systems are generated from the breaking of the molecules when you...
4. ### Need to get rid of the 'h' on the denominator

I'm purely joking, as far as I know, Leibniz and Newton discovered the idea independently of each other :smile: .
5. ### Need to get rid of the 'h' on the denominator

just to play devils advocate :devil: ... Sure, after he stole the idea from Newton! :tongue2:
6. ### Chemistry: Equilibrium

Yes exactly, Silver nitrate is soluble in water, but silver chloride isn't. So adding silver nitrate is like taking away chloride ions from solution...
7. ### Describe a circle as an ellipse?

Think of a circle as having 2 axis perpendicular to each other (like an ellipse) that both pass through the center. What can be said about their lengths? what is the equation of an ellipse, where does the length of the axis show up in that equation?
8. ### Easy calc problem

let I = \int sec^3xdx and let u = secx \ \ \Rightarrow \ \ du = secxtanxdx dv = sec^2x \ \ \Rightarrow \ \ v = tanx using integration by parts we have I = uv - \int vdu \Rightarrow \ \ I = secxtanx - \int secxtan^2xdx using the trigonometric identity tan^2 = sec^2...
9. ### Schools Advantageous of private schools

One real difference between private and public schools is the amount of personal care you recieve. I have friends that go to both public and private schools (I go to a public one myself) and the general concesus is that private schools treat you a little better. For example, private schools...
10. ### Frequency and wavelength!

Well there goes the chance of the OP doing any of the work for himself.
11. ### Frequency and wavelength!

1\f is the period, for wavelength you want to use the equation for all waves v = f \lambda where v is the speed of propogation of the wave
12. ### Decibel problem

hint: first find the distance from the radio the gardener would have to be to here an increase in intensity of 10dB A useful equation is the inverse square law for intensity \frac{I_1}{I_2} = (\frac{r_2}{r_1})^2 where I1 is the intensity at a distance r1, and I2 is the intensity at...
13. ### Stressed over nothing?

I would really like to second what mathwonk has said here. It has been my experience as well that above grades and test scores, teachers recognize genuine interest and effort to actually learning the material. This can go a long way. Of course I would not deny that society evaluates us...
14. ### Locus of points with distance sum =8

their talking about the sum of the distances from A and B. So you need to come up with an equation for the the distance from A and the distance from B seperatly, and then add them... that sum should equal 8 to see the motivation behind this problem look up the definition of an ellpise...
15. ### Book suggestion stickies?

very saddening, this is the only thread here that has 0 replies :frown: to the admin: I can't seem to delete the thread myself, so feel free to kill it whenever you like.