Homework Help

How do i find the square root of a negative number....? Lets say [math] \sqrt -4 [/math] My calculator gives me the answer 0 is it because [math] -a(-a)=+b [/math] where a equals -2(i assume -2 should be its squared root but its not)

Hi Guys, I have to make project on Dengue Fever ( Dengue Fever Causes, Symptoms, Treatment ) , And I don't have much Idea about this. So pls help me- -How the Dengue test is conducted - What medicines are used etc. Pls help me.........

So for my Bio Lab, I have to write an essay on the spread of cancer throughout the body. Like how and why the cells separate from primary tumour and spread to other parts of the body. I read some scholarly journals but, to be honest, they were totally beyond my knowledge of cancer. They were so in depth, and I'm trying to just weed out the core concepts, since this is an intro class. I came up with some key words, like metastasis and clonal dominance theory, but I can't find anything providing a simple explanation of what clonal dominance is or a list of its major tenets. Is the clonal dominance theory not even a theory yet, and just a hypothesis? Because somewhere I rea…

Before saying anything, sorry that my first post on this forum is looking for help. Thats not a good thing, I know. I do intend to post more. Anyway, for my A-level physics coursework I need to give a presentation on a material of my choice...most of the other people in my class got the easier materials / materials with more information on them - I'm stuck with human bones. Ok, any links to information or websites would be really useful. Here are the main topics I am doing about: How strong is the bone? I need to talk about the breaking stress and include some of the young modulus in there too. I need some data about that and possibly compare to other …

I'm reading the intro to calculus on the forum and i'm confused... Basically it states [math]f(x) = (x - 2)(x + 4)[/math] and to find it's derivative you basically have to add the product rule formula, but i got completely lost at the last step,which is is where i need help at, and by the way would it not have been easier just multiplying the function at the very start... I mean i see that in the last step all that was done was just flipping it and then multiplying..

I have been asked to translate into English a number of statements written in set notation based on this introduction. Can somebody talk me through exactly what is being said here? Also, two of the questions use "." to separate terms. I know "Ǝ" means "there exists" and "∀" means "for all"... but what about "."?

I have 42.1167g of Na2CO3. DIVIDED BY RRM (105.99) = 42.1167/105.99 = 0.397mol. Now, I want to find out how many moles there are in 250cm3 when the powder is dissoved in water. Would that be: 0.397*(250/1000)= 0.0993mol? Then, therefore, would (0.0993/250) *1000 get to moldm-3, molarity? I've repeatedly confused myself with something I was able to do a few weeks ago... and a couple of years before that.

[math]\frac{(1+h)^2 - 1}{h} = \frac{1 + 2h + h^2 - 1}{h} = \frac{2h + h^2}{h} = \frac{h(2 + h)}{h} = 2 + h[/math] I'm currently using one of the forums tutorial on calculus... And i'm stuck with a problem. The problem is i know it works out because iv'e substituted "h" with an actual integer, and my dilemma is i can't figure out how it went from, [math]\frac{(1+h)^2 - 1}{h} = \frac{1 + 2h + h^2 - 1}{h}[/math] Ignore the /font font=monospace thing, can't figure out how to remove it

1. Why are π to π * transitions on conjugated double bonds such good absorbers of visible light? 2. Intensity of the HeNe laser (λ=632nm) was measured at 2 distances: 1 m and 200 m from the laser. The meter reading was 10W and 1 W correspondingly. How many photons/sec will enter your eye if you look into the laser from 1 m? From 200 m? Assume that radius of the pupil was 2.5 mm, radius of the detector was 3.5 mm. At a distance of 1 m the laser beam radius was 1 mm. 3. Chl has an absorbance peak at 435nm (Soret band) and a peak at 665nm (Qytransition). Calculate the energy gap (in Joules) between the ground and excited states of these two transitions. An…

hey guys l need your help in my assignment l don't understand what the question wants me to do. .."The transition energy of atomic hydrogen are given by the Rydberg formula 1/lambda= R(1/n2 - 1/m2) where n and m are principal quantum numbers of the two levels. The highest energy series (Lyman) has n=1. Lyman 2 occurs at 97492 cm-1 . Calculate from this value of R(Rydberg Constant) and hence the wavelength and transition energy for Balmer 1.thanks guys!

QUESTION: Describe all the protons that are chemically equivalent to each other, and magnetically to each other. Then, give the Pople notation describing the proton spin system(s) in the molecule. Full marks for proper justification http://imgur.com/VXhQl ATTEMPT TO SOLVE THIS: For the methyl that's 'dashed', I know that the 3 protons on it are chemically and magnetically equivalent. For the sake of naming it, I assigned it as A3. However, I forgot 'why' it is that this is the case. Can somebody remind me of the reasoning behind this? For the wedged proton, I figured that it just stood on its own. Since it's the only proton on that carbon, I called it B.…

Hi guys, So there's a science fair that I'm participating in and I want somebody to bounce off ideas with me so I could come up with the perfect one. I'm thinking my theme for the science fair is environmental cuz that's the stuff that I'm more interested in. Right now, I'm just thinking biofuel/biodiesel and all those boring stuff...definitely not going to win. So... What are some major environmental issues that's going on around the globe? Extinction of species of any kind? New ways for renewable energy that I could expand on? It'd be nice if I could start with something. Thx in advance!

Here's a general chemistry problem and my answer. Would anybody mind checking it? Thanks in advance. 3 Compounds have the following mass ratios of Oxygen:Nitrogen A) 1.143 g oxygen:1 g Nitrogen B) 2.286 g oxygen: 1 g Nitrogen C) 2.857 g oxygen: 1 g Nitrogen Show that these compounds obey the law of multiple proportions. To do this I compared the three compounds to each other. My answer is: A:B = 1.143 g O:2.286 g O = 0.5:1 = 1:2 A:C = 1.143:2.857 = 0.4:1 = 2:5 B:C = 2.286:2.857 = 0.8:1 = 4:5 This whole process seems so sketchy and I was hoping somebody could check this for me. Thanks

The DNA for an H chain in a B cell making IgE antibody for Tularemia has the following structure: 5′-5'—V8—D4—J2—Cε—Cα2—3'. How many individual rearrangements were required to go from the embryonic DNA to this B-cell DNA? I know IgM is the embryonic immunoglobin, so the rearrangements occur from that one. But I have no idea how you figure out which arrangements occur because can't there be thousands of possibilities for the IgM? Also I know IgE has an extra component on the H chain but doesn't IgM have an extra one as well or am I just imagining things? My guess was 4 individual rearrangements but I'm definitely not sure if that's correct.

we have dis competition in school in which we have to take sumthing electronic, dissasemble it and use the parts to make sumthing. Now me and my friends have a cd drive(r/rw), a USB optical mouse, a digital camera and a HP all in one printer (print copy scan). Please give me some ideas on what to make from d parts of these things..need help fast...Thanks in advance

Hi, During the transpeptidation reaction in peptidoglycan biosynthesis when the peptides are cross-linked, is the terminal D-alanine lost [i.e. in E. coli when DAP forms a peptide bond with D-ala of the new disaccharide]? Or does the terminal D-alanine remain and is later cleaved by the carboxypeptidation reaction. Essentially, I'm confused by the difference between transpeptidation and carboxypeptidation. If someone could help me clear it up that'd be great! Thanks!

Hi everyone. I have a question regarding mechanic hoist system of a sailboat. Thanks a lot for your help. Cheers. Your team have been commissioned to design a system to hoist a 250Kg sail up a 35m mast using a winch on a competition class yacht. Speed of hoist is of the essence and the client would prefer that only one grinder (crew) is used. List the assumptions that need verification and the calculations that need to be done in order to achieve a satisfactory conclusion to this commission. A brief explanation as to why you have included each item should be presented.

Hello, I have been having issues getting going with this assignment in csc131. I am to write a CLI program in python where all cards are dealt face down initially in a rectangular grid. On each turn, the player identifies two of the face-down cards. These two cards are (briefly) flipped face-up. If they match, they stay face up. If they don't match, they're flipped back over face-down. The play continues until all cards have been matched; no face down cards remain to be tested. And the grid is determined by a prompt from the user. (At most 9x8 or 8x9) My first issue is creating the list for the deck. I will need to have 2 of each card and I'm not sure how to create the li…

Hello all! I am having a serious conceptual problem here... so our question is: Does it make sense for a processor to have a floating-point square root functional unit but no integer divide unit? I'm going with sometimes, I believe that both functions can be emulated using the hardware given and will give the exact same result and precision...however I am not understanding in what situations one would be better than the other? Can anyone point me in the right direction? I have read all sorts of papers and publications but I am not finding exactly what I need... thanks in advance!

I have no clue where to start but I think it is safe to say that my forward primer could be TAC and my reverse primer TTA (complementary sequences of the start and stop codon) but I dont know what to do after...the problem seems very overwhelming to me! I would like someone to provide me some hints to tackle this! Thanks everyone!Thank you for your help! Question : Write the sequence of two oligonucleotides that will allow you to clone the coding region of gene x in the vector pQE60 using PCR . The coding sequence must be in frame with the ATG of the vector. The histidine tag must be present at the C-terminus of your recombinant protein. The oligos mus…

Hello all, I have absolutely no clue how to start this problem and I would like to have some cues or just something to chew on...thank you!! I know what a plasmid is , I know what sticky ends (cohesive extremities) are but I dont know how the multiple cloning sites in this plasmid are located so im a bit lost! Question: U must clone a DNA fragment having Sau3A sticky ends. The plasmid to be used for the cloning experiment has the following MCS EcoR1, BamH1, Xba1, HindIII *Describe how you would do the cloning experiment. Restriction enzyme recognition sites EcoR1 = GAATTC (the enzyme cuts after the G) BamH1 = GGATTC (the enzyme cust after the first G) Xb…

Can anyone help me with answering these questions? I have mid-semester exam coming up and there are no answers provided for these practice exam.. Q1.An obsessive water drinker ingests approximately 10 litres of water within a day. Select whether each of the following would increase, decrease or not change with the ingestion of 10 litres of water within a day. (i) ECF Osmolarity. (ii) Mean Arterial Pressure. (iii) Vasopressin release from pituitary. (iv) Water reabsorption in the kidney (v) Renin release from granular cells (vi) Angiotensin II levels (vii)Aldosterone levels (viii) Sodium reabsorption in the kidney Q2. In a normal kidney, glomerular filtration …

A.) bONDING B.) VESPR C.) formal Charge D.) hybridization E.) Octet Rule F.) Valency G.) oRBITAL tHEORY H.)Resonance. Using these answers choices why is: 1.) NH4 more acidic than NH3 2.) CH2=CH2 is more acidic than CH3-CH3 3.)Formal Charge of H3O IS +1 AND BH3 IS ZERO 4.) CH2=CH-NH2 IS LESS BASIC THAN CH3-CH2-NH2 5.) H-O-CO-CH3 IS MORE ACIDIC THAN H-O-CH2-CH3

Hello and thanks in advance. 1) Below is a list of common weak acids that can be used to prepare buffers. Listed with each is the pKa for the first proton removed. Weak Acid pKa Conjugate Base H2C2O4 1.19 HC3H5O3 3.86 HC2H3O2 4.74 NH4+ 9.74 For each weak acid, list the chemical formula for the conjugate base in…

This is for physiology lab, so if anyone out there can help me with this, I will worship you. If a 7 year old female patient has a high lymphocyte count of 42%, neutrophils = 51%, Basophils= 1%, Eosinophils = 2% and monocytes = 4% ....what would the likely explanation be of the lymphocytes being out of range AND how many of those cells would be present in 1mm3 of blood? The patients total white blood count is 11,000/mm3. Additional Info: My textbook noted that the following was considered normal WBC, hence how i figured the female patient's lymphocytes were high: Neutrophil 54-62% Eosinophil 1-3% Basophil less than 1% Lymphocyte 25-33% M…