Homework Help

Hello, I'm having a bit of difficulty calculating this limit. [latex]\lim_{x\to+\infty }\frac{1}{\; \sqrt{x+1}-\sqrt{x+7}\; }[/latex] [latex]\lim_{x\to+\infty }\frac{1}{\; \sqrt{+\infty +1}-\sqrt{+\infty +7}\; }[/latex] [latex]\lim_{x\to+\infty }\frac{1}{\; \sqrt{+\infty}-\sqrt{+\infty}\; }[/latex] [latex]\lim_{x\to+\infty }\frac{1}{\;+\infty-\infty \; }[/latex] Well this is where I'm stuck. Naturally the square root of infinity will always remain infinity however it results in an indeterminate form since positive infinity cannot be summed with negative infinity. According to my text book the answer should be [latex]-\infty[/latex] but I have no i…

Tooth enamel contains a compound with the formula Ca10(PO4)6(OH2). Why can a child's teeth be damaged over time if the child is put to bed with a bottle of milk? (HINT: Milk can break down over time to produce lactic acid. I was thinking the solution would be like this : Acid + Base = Water + Salt Acid (Lactic acid) : C3H6O3 Base (Tooth enamel compound) C3H6O3 + Ca10(PO4)6(OH2) ----> H2O + ???????? Thanks for your help, I appreciate it!

Hi,I got this question for a homework: There is an uniform pole with length L, the temperature distribution on this pole has the form T = T1 +(l/L)(T2 − T1) (l is a small L) initially, where T1 and T2 are the temperature at the end 1 and end 2 of the pole, l is the distance between the point on the pole and end 1. Find the entropy change of the pole after it arrives at thermodynamic equilibrium. Assume the heat capacity of the pole at constant pressure is Cp. My solution: dS=(ds/dt)pdT+(ds/dp)TdP (dS/dT)p=Cp/T, a=(alpha) aV=(1/V)*(dV/dT)p So then we have: dS=(Cp/T)dT because fo the constant pressure: Thus: S=integral from T1 to T2 (Cp/T)dT = Cp*ln(T2/T1) T…

http://imgur.com/yVVaucP,6C6ymYY,XzAwRnU,w9MNYAm,1bZ2Tu8#0 Can anyone offer assistance with these questions?

Convert the following differential equation into separable form by using suitable substitution: yy’=x3+(y2/x) When I try to prove it’s being homogeneous or not, I found that yy’=x3+ y’= (lx)4+(ly)2/ (lx)(ly) Factorise it: (l^2x2)+(y^2) / xy Is this considered homogeneous? the l stands for lambda

I am trying to understand the difference b/w tight junctions and desmosomes and have yet to find a major physiological one as they are both used for anchoring cells and both are impermeable. Then if they have nearly identical functions then why can't we have desmosomes in GI tract rather than tight junctions or tight junctions in skin rather than desmosomes in the epidermal layer connecting squamous epithelial cells?

A solution with pH 10 is changed to pH 7. How much stronger or weaker has the solution become? How many more/fewer hydrogen ions are there? I was thinking because each step of the pH scale is 10x stronger/weaker, because pH 9 is 1 step (10x), pH 8 is 2 steps (100x), pH 7 is 3 steps (1000x), the solution has become weaker by 1000x. For the hydrogen ions, I was thinking the same thing applies, am I correct for thinking like this?

.567L of .600M Hydrochloric acid (HCL) reacts with 5.00g of zinc metal. The gaseous product of this reaction is collected over water at 26 degrees C and 100.5 kPa. How many liters of dry gas would be collected at STP conditions? This is a challenge problem from my Honors Chemistry class, and it's been very difficult for me to solve. I'm new to this site, so i don't know how this works. But a good step by step explanation would be perfect! Thanks!

Hello everyone, I am having some trouble with a homework question for my immunolgy class. The question is " It has been demonstrated that mice with a mutation in Toll-like Receptor 4 (TLR4) that differed from the normal TLR4 by a single amino acid were resistant to septic shock caused by fatal doses of gram-negative bacteria. Would this mutation be beneficial or detrimental to the individual with the mutation? Explain." To me it seems that it would be beneficial because septic shock can kill. However, this seems too obvious and our professor never assigns questions that seem this obvious so im hesitant about the answer. Can anyone help me?

if x2+y2+2gx + 2fy +c =0 is on the x-axis, prove that g2 = c. I know that on the x-axis, y=0. x2 + (0)2 +2gx + 2f(0) +c =0 x2 + 2gx +c= 0 (which is a quadratic) but now i'm stuck. solving the quadratic with the quadratic equation formula doesn't help, so what should i do?

Hi! My AP Chem teacher assigned me a set of problems, and this problem in particular is giving me problems. I'm not asking anyone here to completely solve the problem, I know the rule about that. If at all possible, can someone tell me how to start it off? Thanks! Consider the reaction 3A + B + C ---> D + E Where the rate law is defined as An experiment is carried out where 0 = [C]0 = 1.00M and [A]0 = 1.00 X 10-4M. If after 3.00 min, [A] = 3.26 X 10-5M, calculate the value of k.

I'm currently doing an assignment for my biology class, and am stuck on this component of the assignment. Any assistance of any sort will be really appreciated! Any clues? Im really stuck on most of these questions and my TA or prof won't reply. Amino Acid Sequence: MLWVFILAGHDEPFKRLFKKFARKWFDELGSPVLVFVWQGGPFKRLFKKFARKWFDELG 1. How many residues present in the sequence? How would you calculate the specific molecular mass of the protein? How would you calculate the average molecular mass of the protein? 2. Knowing about the factors that contribute to the different types of secondary structure, what will be the most likely arrangement of secondary structure elements f…

I know how to find A inverse. And I know ACA=AB. But how do I go through solving this? I figured it had something to do with the inverse of A. But matrix multiplication isn't the same as normal multiplication. Will something like (Inverse of A)ACA=(Inverse of A)B Since (Inverse of A)A=The identity Matrix CA=B Then CA(Inverse of A)=B(Inverse of A) C=B(Inverse of A) I'm pretty sure all of this is wrong, but even if it isn't, I'm stuck here. How can I solve this and similar questions?

Can anyone help me solve these practice questions or give advice?

I have a question about calculating limits with absolute values. I don't want the solution. Say for example sign of x2 - 1 ___x|_-∞_____-1__+__1______________+∞ x2 -1|_____+___0__-__ 0________+________ sign of x2 + 2x - 3 _______x |_-∞_______-3____ 1_______+∞ x2 + 2x -3 |_____+_____0__-__0___+___ Now my question is how you handle absolutes for example in this case: |x2 - 1| = x2 - 1 or -(x2 - 1) [explain why] |x2 + 2x - 3| = x2 + 2x - 3 or -(x2 + 2x - 3) [explain why] in this case: |x2 - 1| = x2 - 1 or -(x2 - 1) [explain why] |x2 + 2x - 3| = x2 + 2x - 3 or -(x2 + 2x - 3) [explain why] Than…

Can sodium oxide conduct electricity in solution? I know it can't when its solid. Another thing, Does it have a high melting point? Would it conduct electricity in its molten form?

Hi guys, happy holidays. I need some help in choosing the usage of H (enthalphy) and U (internal energy) when dealing with thermodynamics. Any guidelines?

I have a powerpoint that must be done that is on the Tongass National Forest in Alaska. The problem is that I don't know how to get the biomass from there. My teacher made it a requirement, and although there is literally NO information that could be found on the Tongass National Forest he still makes us find it. Keep in mind that everyone has a different ecosystem, so it's pretty hard to find a specific biomass for each ecosystem. Anyways, I've already gone through most credible sites about Tongass but nothing showed up, even in the library. What i'm thinking of doing is some bullsh*ting. How I'll do this is by finding an approximate biomass, but the problem is that I d…

Homework Question: When maternal oxygen is transferred to the fetus and fetal CO2 is passed back, how does this affect the maternal dissociation curve? Does this shift increase the transfer of oxygen to the fetus? --------------------------- My thinking is that the O2 transfer to the fetus will obviously reduce maternal oxygen binding and plasma O2 partial pressure, while CO2 transfer from the fetus will raise maternal CO2 partial pressure. I don't see why the O2 association/disassociation curve itself will change. Also, regarding the second question: obviously O2 transfer is O2 transfer so it will obviously affect it. Will CO2 transfer affect O2 transfer? Will …

An uncoupler is a chemical destroys the proton gradient by poking a hole in the membrane and so the protons from the inter membrane space leak back into the matrix. As a result, you should have less protons going into ATP synthase and thus less ATP. Is this correct logic and conclusion?

Hello I was given this extra credit problem to do over the weekend. I don't even know how to approach it. Any suggestions?

Hey. Ive been struggling to solve this circuit for a while now. They ask you to find v(t) for t > 0. They get 6.25V for the v(infinity). I have no idea how they get that value. Its a first order circuit so it shouldn't take anyone that long to solve. Ive tried every method that I know of to solve for v(infinity) = 6.25... I just dont get that value. By inspection I would have thought it would be 15V with Rth at 8Ohm. If you could just push me in the right direction, as in how to get the voltage across the capacitor at t = infinity, it would be much appreciated. The equation is: v(t)= v(infinity) + (v(0) - v(infinity))(exp(t/tau)) tau = RC…

Hi. I am struggling to understand what I am doing wrong with this equation. They ask for the general solution and then the particular solution afterwards. Given x(dy/dx) + 5y = 7x^2 , y(2)=5 => dy/dx + (5/x)y = 7x integrating factor: e^integral(5/x) = e^(5lnx) = x^5 multiply by this gives: x^5(dy/dx)+(5/x)y(x^5)= 7x^6 => Dx[(x^5)(y)]= 7x^6 integrate both sides => (x^5)(y)= x^7 + C => y(x)= x^2 + C/(x^5) (divided by x^5) ok thats the general solution Now I get the particular solution by subin in (2,5) so 5 = 4 + C/32 so C = 32 sub in and you have an answer... The answer they give is y(x)= (x+4x^-…

Hi Can you help with this problem? I've been arguing with a classmate. Thanks in advance Chromosome 22 has about 700 genes in 48Mb of sequence, which represents 1,5% of the estimated 3200 Mb in the haploid genome. Using these numbers, how many genes would you estimate for the haploid human genome? If your estimate is significantly larger or smaller than the accepted value of 25,000 genes, suggest possible explanation for the discrepancy. Is it as simple as a rule of three? if a chromosome contains 700 genes, 1610 genes contain 23 chromosomes, you agree? If that's how it resolves, then the reason for leaving fewer genes that are actually doing, is by the high d…

I am trying to find the theoretical yield and percent yield in nitrotoluene. The question: Exactly 4.0 mL of toluene (density = 0.87 g/mL) were reacted with excess nitric acid in the presence of excess sulfuric acid, and 3.6 g of nitrotoluene were obtained. So I started with the balanced equation: C7H8 + HNO3 --> C7H7NO2 + H2O Then I calculated the grams of toluene: 4.0mL * 0.87g/mL = 3.48g C7H8 Then I calculated the moles of toluene: 3.48g * 1 mole/92.138g = 0.038 mole C7H8 Then I calculated the moles of nitrotoluene: 3.6g * 1 mole/137.136g = 0.026 mole C7H7NO2 This equation is a 1:1 ratio so I can't multiply by anything, so trying to find th…