Mathematics

A coworker of mine phoned with this problem. You have been asked to create at least 1000g of a mixture of sunflower seeds and raisins. The mixture must contain at least 75g of dietary fibre, but no more than 40mg of iron. Use the chart below to determine how many units of sunflower seeds (1 unit is 100g) and how many units of raisins (1 unit is 100g) should be used to minimize the cost of producing this mixture. Dietary fibre (g) 10 g / unit sunflower seeds Dietary fibre (g) 5 g / unit of raisins Iron (mg) 4 mg / unit Sunflower seeds Iron 2mg / unit raisins I’ve worked out a system of e equations, and have tried to graph the problem. But I don’t know…

I'm learning how to use MatLab & Maple. But I wonder if there is a really good, free alternative to these programs. What do you think of SciLab & GNU Octave (vs. MatLab) ? ...or Maxima (vs. Maple or Mathematica) ?

I have been doing a little fooling around with math(yes I realize how uber nerdy that is) and I may have found a Fermat’s last theorem type problem that is: If x is an integer grater then 1 there is no solution for y^2 = x! or possibly(I doubt it) A^b = x! if y, a, and b are integers. Probably one of the larger factorials proves me wrong but I am just putting it out there.

Hello, Is it possible to combine the following functions into one? x := 0.5m ft(z) := if(z<=x, f(z), f(x)+f2(z-x)) f(z) := 850*g*z f2(z) := 1024*g*z ft(z) calculates the static pressure at depth z in a 0.5m layer of oil on top of water. So if z is in the oil the result is just f(z), but if in the water layer, f(0.5)+f2(z-x). My fluids lecturer hinted that this kind of problem can be solved without the use of ifs, but didnt seem eager to expand! I'm wondering if it can be solved through knowledge of the pressure-depth gradients of each fluid... but it's mirky!

Hi all. Looking how to calculate the power developed by an undershot water wheel spun by a laminar flowing river in function of -Flat paddles submerged area, -Speed of river ignoring friction losses. http://commons.wikimedia.org/wiki/Image:Undershot_water_wheel_schematic.svg Thanks.

Hey All, At first watch I was at a loss of how they developed such creative mathematics and architecture. After no sleep I came with this conclusion, if you would be so kind as to scrutinize: In the development of mathematics the progression could be described as having evolutionary traits. As much as we love to learn just for the sake of sating a ferocious curiosity we unfortunately would not get as many grants as the people claiming that their math/physics can better mankind. So our math tends to follow the needs of the time. In the case of western civilization you see an abundance of grid/simple geometric systems from street layout to pipeline. In the case o…

I saw a very interesting thread in the archive on infinity. Why was it archived, which basically killed the thread? I would have replied, but I can't.

Hi guys, Its been a while and my brain has gne soft, (blows the dust off the chess set). Right, I've got a LED it is a 2.5V at 11mA I've got a battery at 1.5V 1800mA How long would the battery last if the led worked at this low voltage. worked it out and I got some silly number, something like 43 sec's. Can someone show me the way this would be worked out so I know for the future. My cals were: (1.5 * 1.8)/(2.5 * 0.011) That says my led would only last 108s, my maths has gone!!! Jon.

If you project a helix onto a 2D plane from a perspective normal to its axis, what type of curve is the result, and what formula describes it? Another way of putting it: If I want to draw a side-view of a twist drill bit, how do I draw the flute? Thanks!

Ok for my homework tonight we had to do problems like these: I=?,P=12,000,R=7%,T=2years I=Intrest P=Principal R=rate T=Time I=83.00,P=6000,R=?,T=3years I got how to do those(IChose random numbers) But I need help trying to get I=125,P=?,R=6%,T=6years How do I get the principal? We never learned it in class

I'm trying to figure out the name of the theorem in which one sphere is cut into infinitely small pieces, and when put back together, it has the possibility of creating two spheres of the same volume as the original sphere. Can you help me?

Can anybody describe to be "in basic" terms what is a Platonic solid? And why are there only five? Also what does it mean to say that the faces, angles and edges are all congruent? Thanks

Consider an n-dimensional complex vector space. The corresponding vector space of nxn matrices is n^2 dimensional. I want to find out if there exists a basis for this space consisting of semipositive matrices. The question seems simple, but I can't find a proof. any help is appreciated.

An axiom to settle the continuum hypothesis ? (Logic Colloquium 2004 contributed abstract) Paul Cohen used a set of generic reals to prove the consistency of the negation of the continuum hypothesis with other axioms. It is my opinion that such sets do not really exist for a Platonist. My opinion is that the continuum hypothesis is true. Here is a tentative axiom from me to try to prove it. Axiom : An infinite subset of the power set of N has a bijection either with a countable union of (pair wise disjoint) sets of n elements or with a countable Cartesian products of (pair wise disjoint) sets of n elements. Mr Andreas Blass proved that this axiom is equiv…

Hi all, This is my first post in this section of the forums! I was doing some past papers and I am stuck in this question. Need help any1.I am not very good at maths! I am doing A’ levels by the way. Q. Solve the equation for angle in the range -180 ≤ Ф ≤ 180. 4 Cos2 Ф + 5 Sin Ф = 3 My solution is: 4 (1- Sin 2 Ф) + 5 Sin Ф -3 = 0. 4 – 4 Sin 2 Ф + 5 sin Ф -3 = 0. -4 Sin 2 Ф + 5 sin Ф = 0. Assuming sin Ф = x, then -4x2 + 5x + 1 = 0. Using quadratic formula: x = -b -+ √ b2 – 4ac 2a x = - 5 -+ √ 5 -4(-4)(1) -8 So x = -5 – 4.58 …

I spent a little bit of time yesterday looking at magic squares yesterday (something which I havent done since school) I noticed that sudoku puzzles are basicly magic squares but they reuse each number 9 times. Sudoku puzles are in essence very easy to make. Simple count up and loop back to 1 after 9. and offset each row so that it there is never the same number in each colum. 1 2 3 l 4 5 6 l 7 8 9 4 5 6 l 7 8 9 l 1 2 3 7 8 9 l 1 2 3 l 4 5 6 2 3 4 l 5 6 7 l 8 9 1 5 6 7 l 8 9 1 l 2 3 4 8 9 1 l 2 3 4 l 5 6 7 3 4 5 l 6 7 8 l 9 1 2 6 7 8 l 9 1 2 l 3 4 5 9 1 2 l 3 4 5 l 6 7 8 each number can be switched with any other and the order of the colums a…

One reason why the negation of the axiom of choice is true We apply set theory with urelements (non sets) ZFU to physical space of elementary particles; we consider locations as urelements, elements of U, in number infinite. Ui is a subset of U with number of elements n. XiUi is the infinite cartesian product and a set of paths. Let us consider the set of paths of all elementary particles-locations which number is n. If n is greater than m in CC(2 through m), countable choice for k elements sets k=2 through m, the set of paths will be the void set. So, after an infinite time, physical space would become void, the universe would collapse and a Big Crunch woul…

Dont tell me the answer but how easy is this to do? X = 3 √(X+3)3 - (X+1)3 + (X+8) 3 find X...

I have problem with getting normal coordinates offset. I have cube1 and cube2. cube1 position is 10,10,10 and cube2 position is 10,9,10. Cube 2 offset refers to local coordinate system of cube1. If rotation of cube1 is 0,0,0 i get position offset 0,-1,0. But if cube1 rotation is 45,0,0 i get offset 0,-0.7071,+0.7071. The problem is that offsets dont use normal coordinate system, they use local coordiante system of cube1. How do i get offsets on normal coordinate system?

A quick problem. Requires a little high school math reasoning. (x^2)(y) = x (z)(x) = y x, y, and z are not zero, +/-infinity, or +/- 1. Solve for x, y, and z. (there is a solution)

kudos for anyone who solves this. This pattern goes on forever: 0, 1, 1/2, 2/3... What would be the limit as the pattern approaches infinity. In other words, whats the last number in the infinitely long pattern? example: 1.9, 1.99, 1.999 evenly approaches 2.

I put this challenging puzzle in the “Brain Teaser and Puzzles” forum but nobody tried to solve it so far, so I decided to post it in this forum as well. I hope it does not amount to a “spam”.

A common way of constructing a pseudovector p is by taking the cross product of two vectors a and b: p = a × b. As x goes to −x, y to −y and z to −z, a and b go to −a and −b (by the definition of a vector), but p clearly does not change. Is it right to say that every vector is a pseudovector as per the above stated defination,as we can represent any vector as a cross product of two vectors?

So i had a trig test today, and my teacher marked off a problem, and ive reviewed it plenty of times, but cant seem to figure out what i did wrong. Could someone please help me with this, i am simply converting to standard form of an ellipse/hyperbola. The equation is x^2 + 4y^2 +2x +16y = -1 . I believe that my answer was something like ((x+1)^2)/4 + ((y+2)^2)/1 = 1 . I am not possitive if that was my exact answer, but i am sure the problem is exact. I think i got it right and just neglected to show some valuable piece of work, and my strict math teacher counted it off. Thx in advance for the help, and i appologize for not using latex, i was in a hurry.

Which of these two tend toward zero slower? In other words, which one will eventually remain larger than the other for all x greater than an arbitrary finite number? f(x) = 1/(x(lnx)^2) f(x) = 1/((ln(3^x))^2) Sorry for the prolific use of parentheses; I wanted to make the functions very clear.