Homework Help

f(x) and g(x) are differentiable on 0 f(0)=g(0)=0 calculate [math] \lim _{x->0}\frac{cosf(x)-cosg(x)}{x^2} [/math] ?? it looks like cauchys mean value theorem F(x)=cos(f(x)) G(x)=cos(g(x)) what to do next??

I'm doing an exercise that gives me a list of equations and asks me to identify which ones are ordinary differential equations (hereafter DE). The solutions in the back of the book say that (1) y'' + (2/x)y' + e^(-y) = 0 is a DE, but (2) y''' - (1/(x^(1/2)))(y^(3/2)) = 0 is not. I don't understand the difference between these two equations. Both contain only an independent variable x, a function y(x), and that function's derivatives. So why is (1) a DE but not (2)? Is my textbook's solution wrong? I can't ask my teacher because I'm not in a class; I just wanted to learn about differential equations so I got a book.

How do I prove that: (cosx-cos3x)/(sin3x-sinx)= tan2x?

i have some data which is not normally distributed as the mean is not equal to the median however it is very close. I need produce a grpah in excel which demonstrates the population by the area underneath the graph like a normal distribution graph. How would i do this?

1- After bacteria are grown for many generations on a medium containing normal, nonradioactive phosphorous (P), some are transferred to a medium where all the phosphorous in the form of its radioactive isotope, P32. The bacteria use this P32 to synthesize the deoxyribonucleotides they need for DNA replication. The bacteria grow on this P32 for three generations and a sample of bacteria is removed at the end of each round of replication. DNA duplexes from these samples are isolated and analyzed for P32 content. a. For each of the three samples of bacteria, estimate the proportion of duplexes that would have (1) all of their nucleotides containing P32, (2) some of t…

Honestly, I'm doing my sister's homework, AND I HAVE NO IDEA WHAT THIS STUFF IS ABOUT. So can you help me with this question: Create a scenario to illustrate simple classical conditioning. Be sure to label the neutral stimulus (NS), unconditioned stimulus (UCS), unconditioned response (UCR), conditioned stimulus (CS), and conditioned response (CR).

hi all, I was just wondering if the d6 ions can have spin-only magnetic moment in a tetrahedral field which gives the value 2.83 BM? I cant see that happeing becuase in tetrahedral field the spin is HIGH, and we have 4 unpaired electron to give 4.90. We dont observe the low spin in which case the spin-only magnetic moment will indeed be 2.83. I am confused, I have got a question which asks why d6 ions in tetrahedral field have the magnetic moment 4.90 BM or 2.83 BM while 4.90 BM or 0 BM in an octahedral field. But it does ask which one of the 4 values are not observed in practice!

I have no idea how to find the real part of [math] z = e^{(1-i\frac{pi}{3})} [/math]

"Explain how potassium ions are formed. Your answer should refer to the octet rule, include electron configuration or electron dot drawings (as used in the lecture notes), and indicate whether potassium ions are classified as anions or cations." This is the question I have been given and I'm a bit lost. I've read that the elements change their electrons to be like the nearest noble gas but potassium is so far away from the gases I'm not sure which one... or if that's even right to begin with.. Any sort of help in this area would be greatly appreciated

Here's a problem that ought to be straightforward. I want to minimize 40x1+30x2 I even know the answer. The optimum is x1=30, x2=0. The constraints are: .4x1+.3x2>=8 .2x1+.45x2>=6 .3x1+.1x2>=7 .1x1+.05x2>=3 Now, of course, the two-phase approach would seem to work. I.e. first try to minimize four slack variables, one for each constraint, until you get a feasible solution -- then optimize the feasible solution. Well ... I tried plugging this into an applet that uses the two-phase approach and it does the first phase in four iterations! But they don't make sense! The applet is here: http://neos.mcs.anl.gov/CaseStudies/simple…

I am trying to integrate [math] \int\frac{dx}{x\sqrt{x^6 -25}} [/math] I tried using algebra to change it so it easier to use substitution to complete the integration. Here what I did: [math] \int\frac{dx}{5x\sqrt{(\frac{x^3}{5})^2 -1}} [/math] How can I approach this problem? This is just a problem out of my book for practice. I do have the solution to the problem.

Hi all, First time here; I was just looking for help on a couple of Biomechanics questions I have: 1. You are moving into your new apartment and you are pushing a bookcase across a carpeted floor. The coefficient of friction between the bookcase and the floor is 0.65. What force is required to move the bookcase if its mass is 40 kg. Assume gravity equals 9.81 m/s². 2. In a Nike shoe design laboratory, the frictional properties of a shoe are being tested. The shoe is placed on a piece of board and then one end of the board is raised. The raising of the board from one end creates a slope. The board is continuously raised from one end until the shoe begins to …

Hi, This is my first time posting, I hope you can help. Designing a belt system. Two pulleys, two tensioners. 5 m circumference of belt. Found moment of inertia of pulleys and tensioners Found moment of inertia of belt added the two: 0.742750068 then used K.E= 1/2 * I * omega^2 to get rotational energy at full speed (1200 rad/s) K.E = 53478004.91 joules SEEMS EXCESSIVE!! want to find motor power required to run this. so i chose an acceptable start up time 60 seconds for the 187 kg belt to reach 30 m/s however this told me I'd require a 891KW motor Can anyone help me figure out where im going wrong?? p.s. mass moment of inertia for belt was calcul…

Hi, Ok, so i'm new to bioinformatics and don't really know what im doing! I am doing an assignment on tumor protein 53 and have been using the NCBI website and at the moment im stuck on a question. For the information below, I am supposed to find the nucleotide sequences of the gene (which is the sequences under the origin heading yes?) and the amino acid sequence data which I have been told is under the Features heading, though I have no idea how to read the information given! Any ideas? FEATURES Location/Qualifiers source 1..2331 /organism="Homo sapiens" /mol_type="mRNA" …

Question A neutron and a proton collide with a kinetic energy of 150 MeV. You may assume that a neutron and a proton each have the same mass energy. Given that a pion has a mass energy of 140 MeV, which of the following reactions are allowed and which are not allowed? n + p → p + p + π– n + p → n + p + π+ + π– n + p → n + n + π0 n + p → n + n + π+ + π– Reaction allowed? If not is it due to Energy conservation &/or Charge conservation I had thought that the middle two were allowed How do I work out the conversions?

Just for the record, yes, I am quite capable of preparing a conventional resume. But due to the fact it is for my father, I am unaware of how to construct this particular resume... Also, I ask here because I assume you people have a good deal of experience applying for jobs and what-not. Well, the reason I'm having trouble is that my father has been self employed for the last 30 years...he's been a farmer, and Im not sure if you would put that in the jobs section...would you? How would you go about describing his job? And he can only do basic stuff with the computer...but he is an incredibly intelligent man...It took me only an hour to explain differentiation …

Hi everyone, i really find this forum helpful as i am just finishing my first year (foundation science) in order to go on and do an Environmental health degree. i didnt exactly do well in my science GCSE 7 years ago. so my question for now is, im doing an assignment on biodiversity (which is due in very soon...my bad for not asking earlier), we went to some woods, from a 30x30m plot of woodland, we noted down all of the species and how many there were of each species. i have calculated the shannon weaver diversity index of every groups results, the groups who were in the woods with less species and less trees in general have a higher diversity number....does that make…

hello every body, in this thread you can request the articles that you need you should follow these rules for any request: Title: required Author: required Journal: required Year, volume, issue, and the page range: required Full text link : (try your best to find this)

A long thin rod lies along the x-axis. One end is at x=2.00 m and the other at x=3.00 m. Its linear mass density l =0.400 x2+0.600, in kg/m. Calculate mass and the x-coordinate of the CM of the rod. Can anyone help me out here? I have no idea how to set this problem up

Our teacher set us this problem and said he wont give any answers until somone gets it. No one has any idea how to even begin it. Help? "How old are your three children?" the mathematics master asks his former student. He is told their ages add to 13, and multiply to give the number on his study door (which they can both see). "I will need to know more", the master says. After a few moments reflection. "The eldest one is learning to play the violin", replies his former pupil. "Ah! in that case I can now give you their ages", the master tells him, and does so correctly. How does he know? What are their ages? What is the number on the door?

So our assignment is to build a vertical egg launcher. materials are all inclusive. the egg can be in a container - our plan includes a protective box the size of a tissue box. the launcher must be able to fit in a 3 meter2 box and be able to be lifted by two high school aged kids. it is graded by time in air and points are subtracted for horizontal travel distance. any ideas????

Hi. I'm doing an experiment for science where we test the effect of colour on childrens memory. Most statements I can find apply directly to adults not children - which will be good if there is a specific reason why children remember colours more... Heres our opening paragraph: Focus on the bit in bold firstly, am I correct in saying this? and secondly how can I expand on this further and more relevant to our report? Help appeciated:D!!!

Forget it, my friend already helped me.

pretty much I have to write an essay about energy production in japan. If any one knows any good sites please post them on the thread, I would greately appreciate it

I'm doing an experiment with aluminum wires, and when I put them in saltwater, they starting growing these orangish blobs. Then, in regular water, they looked darker in some parts. In air, obviously nothing happened. Can anyone explain what the heck happened with the wires in saltwater because I'm clueless right now? :confused::confused: