Mathematics

First off I am not the greatest math student but I have been having an argument with a person I know who is convinced the earth is 6000 years old lol. He doesnt believe carbon dating to be true but then I brough up Pangea and he agreed that alot of geological evidence shows Pangea was fact. Well the math problem is how would I calculate the time it would take for continental drift to bring the plates to where they are today? I would need to know the following: speed of continental drift, approx position of Pangea landmass and the current place of landmass. I am 100% sure it accounts for well over 1 billion years or more but I dont know how to figure it out prope…

This is a problem similar to one is Stewert's Early Trancendentals: A boat is being pulled towards a dock by a rope. The rope is reeled in at a constant speed. What is the speed of the boat moving across the top of the water when it is a certain distance away from the dock? (x and y are perpendicular) The solution is fairly straight-forward: Use the relationship between the distances [math]r^2 = x^2 + y^2[/math] Differentiate in time: [math]2r \frac{dr}{dt} = 2x\frac{dx}{dt}[/math] Here, dr/dt is the speed of the rope (constant) and dx/dt is the speed of the boat. I will now call these vr and vb. Finally: [math] v_b = v_r\frac{r}{x}[/math] This is the solutio…

Hi, I was wondering where you can find resources and tips on contest math and similar problem solving type questions. I really want to develop my reasoning and problem solving skills. Thanks a bunch.

hello im new her this is only my second post so i dont know if i put this in the correct place or not but yeah... my problem is that on a test today my teaches asked us to factor: 2(x)squared+13(x)+15 i factored it out and got (2x+10)(x+1.5) my reasoning is as follows 2(x squared+6.5x+7.5) i divided by 2 2(x+5)(x+1.5) factored the terms (2x+10)(x+1.5) if you F.O.I.L. out the terms you get the original equasion (which i thought was "factoring" but however my teacher got a different answer) after thinking over this for a while i came to the conclusion that the term "factor" should have been replaced with "find the simplest factor" because what i had was a facto…

is the answer 64??

I've been doing exercises that require simplifying expressions since forever, but I don't think I ever questioned what it actually meant. The reason I ask was that I came across this expression: [math](\frac{x+y}{y+z})^{2}(y^{2}-z^{2})[/math] And tried to simplify it, I got to [math](x^{2} + y^{2} + \frac{2xy}{y+z})(y-z)[/math] and then thought, hey, is that actually any simpler?

Is there anyway to solve an equation (without logarithms) such as: [math] 2^x=x^2 [/math] and [math] 2^x=x^3 [/math] where x is in the exponent and the base of two different terms? If so, how?

Can anybody give that answer for this please :: Circular bylinder of R=6cm is concentric witht the Z-axis btw z=-3cm & 3cm find the volume.

Hi, I need help with this question is this right? Thanks

For odd reason, the Latex in this forum doesn't show up to me. It shows up as an image with "x" as "not displayed." I can still read the code if I put my mouse over it but I'm not sure what happened. Is there something in my setting that I have to do or..?

I recently heard of a different kind of implicit differentiation, apparently it works like this: [math]\frac{dy}{dx} = - \frac{dt}{dx} \div \frac{dt}{dy}[/math] Where t is a made-up variable. This makes complete sense to me except for the negative sign. Why is there a negative sign and what is the name of this method?

Actually, is there any way how to find the lograthm of a number WITHOUR USING THE LOG TABLES ITSELF?? Is it possible? Please give a detailed explanation and steps to do that.

Hi all, would anyone be able to give me a little bit of help with this question. for part (a) i did this.... our sphere is given by [math] x^2 + y^2 +z^2 = 25 [/math] putting in z = 3 to find out part of the sphere gives: [math] x^2 + y^2 = 16 [/math] so we change to the parametric representation of the part of the sphere we are interested in sphere which is [math]\vec{r}(\theta,\psi) = (4sin\psi cos\theta) \vec{i} + (4sin\psi sin\theta) \vec{j} +(4cos\psi) \vec{k} [/math] then [math]\vec{r_\theta}(\theta,\psi) = (-4sin\psi sin\theta) \vec{i} + (4sin\psi cos\theta) \vec{j}[/math] [math]\vec{r_\psi}(\theta,\psi) = (4cos\psi cos\…

Not sure if this belongs in the Physics or Math forum. I'm leaning towards Math more. Say, when scientists do experiments, record data, and come up wtih a formula, how do they prove that the formula is correct? I'm talking about those formulae that cannot be mathematically derived. One example might by Hooke's Law.There will inevitably be some error so how do they prove, besides just looking at the graph, that the formula should still stand in spite of the errors affecting the data? I know that they can't prove that the formulae is 100% true, but they can show, using statistical analysis that the formula is highly unlikely to be untrue. My question is, HOW? Say I'…

I noticed a pattern when you would square a number and add the digits together... ex. 15*15 = 225 2 + 2 + 5 = 9 1 - 1 2 - 4 3 - 9 4 - 7 5 - 7 6 - 9 7 - 4 8 - 1 9 - 9 10 - 1 11 - 4 12 - 9 13 - 7 14 - 7 15 - 9 16 - 4 17 - 1 18 - 9 19 - 1 20 - 4 I won't go any farther, and just assume that it keeps going. Does anyone know why though? as in a proof as to why?

can someone give me a formula for an aproximate calculation of the time by the value of X from the table and the graph attatched? cm3 of Thiosulphate.doc

I was doing an exercise diffentiating things like (2+3x)4, which was fairly easy, being given the rule: if y=[f(x)]n then (dy/dx)=n[f(x)]n-1f'(x) But then, to my horror, another number turned up that I didn't know what to do with, there was a question like so: 5(2+9x)3 and I just don't know what to do here! Could anyone give me a nudge in the right direction?

Not sure if this is the right section or not but... I have a problem with my Ti-83 In the list edit menu there is no L1 I have to use L2, L3 .... I have tried clearing them memory. I've tried taking out the primary batteries. What else should I try? Thanks for any help. If there is a better section for this thread, please move. Thanks Nic

This is fun: http://www.planarity.net/ I managed to get up to level four without too much difficulty. Edit: woo! Level six.

Two nice mathematics articles in Seed magazine http://www.seedmagazine.com/news/2006/09/putting_his_money_where_his_ma.php http://www.seedmagazine.com/news/2006/09/maths_architect_of_beauty.php

I dont know where i should put this question...please forgive me if i put this in wrong place... i have no idea how to prove this boolean algebra equation are equivalent: x'y' + xy = (xy' +x'y)' x'z + xy = x'y'z + yz + xy thank u very much for your help...

K i got this application question the other day in my introduction to calculus class and i was wondering if anyone could lend me a hand. Katie is building a wooden rectangular storage box. The box will have an open top and a volume of 1.5m cubed. For design purposes, Katie would like the length of its base to be triple its width. Thick wood for the base costs $8/m squared and thinner wood for the sides costs $5/m squared. a) Express the cost of the wood as a finction of the width of the base. b) Find all possible dimensions if Katie spends $44 for the wood. c) what dimensions would you recommend? Why? Now, i think if someone could help me with a) then i probabl…

I have this problem for my Calc class and, though I've done it manually and through my calculator, WeBWorK keeps telling me I'm wrong. I hoped someone could tell me if I'm interpreting it incorrectly or maybe just doing the wrong calculation. To me, this means that I must find [math]\int t^2 e^{-2 t} \ dt[/math] According to everything I've tried, this equals [math]e^{-2t}(-t^{2}/2-t/2-1/4)[/math] What am I doing wrong here?

Here's an incredibly simple math problem that I for the love of god cannot figure out.... help.... f(x)=(1/4)x^4 - (3/2)x^2 + 2 I need to set that to zero. I know I did this, and this is a review problem. But for the love of god I have no clue.

If (a,b)=1 , i.e. they are relatively prime to each other, b^d = 1 (mod a) where 1=< d < a-1 , how do you prove it? Also the following is my guess. IF b^h= 1 (mod a^2) Then d l h, does it make sense?