Mathematics

Hi everyone, im new here but i need some help Ive been asked to find the angle between the gravity and gravitational vectors as a function of latitude where gravity is pointing to the center of the earth and the gravitational vector is the sum of the gravity vector and centripetal vector. Can anyone help? Thanks

hi, While solving a calculus problem today related to "cross sections" I derived a formula to calculate the area of an equilateral triangle. So I was just curious whether the formula I came up with is already in use or it's....? The formula: [math]A(s)=\frac{s}{2}\sqrt{s^2 - \frac{s^2}{4}}[/math] What do you guys think?

The title for this post is inappropriate sorry, I hit post when I should have hit preview. I'm trying to re-arrange the first equation in the series below to the format [math] y=a(x-p)^2+q [/math] Using the completing the square method, now I have a process down where I get the right answers. But I don't understand what happens to the "8x" them in the last step...I just leave it out and take the sqroot of the "16" and the "x^2" to get the (x-4) in brackets? I don't fully understand why one-half of the coefficien of the x-term is added and subtracted either? [math] F(x) = 3x^2-24x+40 [/math] [math] F(x) = 3(x^2-8x)+40 [/math] [math] F(x)…

why is y=-f(x) a reflection of the graph y=f(x) accross the x-axis?

This is from the book, need help changing it into mathematical model. "Consider a tank used for certain hydrodynamic experiments. After one experiment the tank contains 200 litres of a dye solution with a concentration of 1 g/litre. To prepare for the next experiment, the tank is rinsed with fresh water flowing in at a rate of 2 litres/min, the well-stirred solution flowing out at the same rate. Find the time that will elapse before the concentration of dye in the tank readches 1% of its original value."

OK this has been annoying me, I'm sure it's relatively simple and I'm just missing something... like the power of thought... show that: [math] \sum_{l=0}^{n-1}(2l+1)=n^2 [/math]

How would you factor: A^3 + B^3 + A^2 - B^2

Basically, I've slept through most of my basic education, and now I'm lusting for some Maths. The problem at hand is this: in what sequence should I go through the subjects? I got CliffsQuickReview Basic Math and Pre-Algebra, and since I'm about to be done with it, I was wondering what should be next on my list: Algebra, Calculus, Trigonometry, etc. I would appreciate it if someone gave me a proper summary that spanned subjects and their sequences. How many Calculuses are there--as in Calculus 1, Calculus 2, etc? How many Algebras? etc. Thanks in advance.

Hi all, Have been having some problems with the following math problem I was given last week: A solid cube of mass M and side a has one corner at the origin and three sides along the positive x,y and z axes. The square of the distance of the mass element dM = pdV rom the z-axis is x^2 + y^2 so that the moment of inertia of the cube around the z-axis is given by I = integral (x^2 + y^2) pdV taken throughout the volume V of the cube. If the cube has constant density, prove that I= (2/3) Ma^2 Any help/tips would be most appreciated!

I cannot find a way to prove this: A function r(n), where n is a positive integer, gives the number n with its digits inverted. Prove that for positives integers a and b, the two numbers 4(a^2) + r(b) and 4(b^2) + r(a) cannot be simultaneously perfect squares. Can anyone help me?

I'm currently taking pre-calculus and I'm learning that, when there is a constant c, then the equation of c = xy is the equation for an inversely proportional relationship of x and y. This makes sense, because if x decreases, y has to increase to keep c at its current constant rate. However, is this really the only inverse proportionality equation? It seems to me that c = x + y would also be inversly proportional, since 7 = 2 + 5 as well as 7 = 6 + 1. Notice how when one goes up, the other goes down, which is really the only requirement for an inverse proportionality relationship. Am I right, or am I stoned?

Anyone know how to factor on a TI-83+?????????

When solving a system using augmented matricies, how do u know when if the solution is inconsistent, if you continuously are trying to get th identity matrix

Hi, I have read from somewhere that random numbers generated by computers are really pseudo-random numbers in reality. If this is true, could anyone tell me what kind of patterns exist in the random numbers generated by computers that make them pseudo-random numbers? thx.

Hello could you please explain me with easy words how do you find out the domain and range of a function, for example f(x) =(x+5)^3+2 how would you know the domain and range of that function? thank you

hello I'm asked to write the equation y= 2x^2-4x+6 in the form y= a(x-h)^2 this is what i have been doing first I divide by 2 x^2-2x+3 then I try to complete the square (x^2-2x+1)+3 (x+1)^2 now i don't know what else to do Should I multiply that one times 2 because I divided by two and then add it to 3 to get 5? and so the answer would be (x+1)^2+5 But I know that's wrong because I graphed both equations and they aren't the same graph please help me.

Could you find all positive integer solutions to ... x^y - y^x = x + y

The theory that I am attempting to formulate is being complicated by the intrusion of ancient Greeks into the mix. Their number system is decimal in nature (probably lacking zero). My question is this. How old would a decimal Greek number system be likely to be? Could it be older for instance than the Arabic Islamic system which, by definition, must be newer than 500AD I always believed that the Muslims invented the decimal system. A date would be useful. :-) :-) -------------------------------------

So I have the equation y=x^2 - 2x-5 I graphicaly determine the zeros to be 3.45 and -1.45...shouldent I be able to substitute these values in for x and solve the equation...which should be zero. 3.45 gives and answer near zero 0.0025 (perhaps rounding error) but -1.45 is nowhere close. What's the deal? Nic

Hi all. Now i got confused; this site: http://www.mathopenref.com/subtend.html shows the subtended angle for the sun being 32 arc minutes or 0.52 degree. That seems very small. Does it mean that in a 12.0 hour day, the sun path could be drawn as 346 sun disks fitting edge to edge on the sky ? Am trying to create a formula, chart or nomograph to calculate the needed diameter of a distant mirror reflecting the entire sun disk. (As a heliostat of what diameter positioned at a given distance will show the complete sun disk) Miguel

is the answer 20 days?? sorry for such posts!! i am preparing for few exams and these questions are killing me because i make very silly mistakes in Maths. kindly bear with me!!

This is awesome: http://en.wikipedia.org/wiki/Proof_that_0.999..._equals_1

I thought it was nice, even though if he started multiplying figures with numbers like 6 or 8 it would be pretty tedious Math Lesson: A new way to multiply

Hi, I am having trouble with this question Assume that a blood vessel, such as a vein or an artery, has the shape of a cylindrical tube with radious R and lenght L. because of the friction at the walls of the tube, the velocity, v, of blood flowing throught the blood vessel is greatest along the central axis of the tube and decreses as the distance r from the axis increses unitl v becomes 0 at the wall. the relationship between v and r is givin by the law of laminar flow, discovered by the French physician Poiseuille in 1840. the law V= p / 4nl (R^2 - r^2) where n is the velosity of the blood and P is the pressure difference between the ends of the tube. If P …

Hi, can someone help me with this question? Three resistors, R1, R2 and R3, are connected in parallel in an electrical circuit. The total resistance, R, in ohms is given by: 1/R = 1/R1 + 1/R2 + 1/ R3 R, R2, and R3 are increasing at rates of 0.1, 0.5 and 0.7 ohms/s, respectively. Determine the rate at which R1 is changing when R = 50 ohms, R2 = 70 ohms, and R3 = 60 ohms. Find R1 1/50 = 1/R1 + 1/70 + 1/ 60 (1/50)-(1/70)-(1/60)=1/R1 How do you solve something that is in the deominator? the i just Plug eerything in to the equation d/dt 1/R = d/dt 1/R1 + d/dt 1/R2 + d/dt 1/ R3 right?