sysD

Ok, so I'm a bit stuck. Here's the problem: log(base9)(x-6) + log(base9)(x+2) = 1 Here's my work. At first i simply tried to solve by rooting: (x-6)(x+2) = 0 x = 6 or x = -2 But realized this would not work, as any rooting would result in having one of the logarithms above yield an invalid result (eg. log_9(0) ) I've tried another way (isolating x), but I'm stuck. (x-6)(x+2) = 0 x^2 + 2x - 6x - 12 = 0 x^2 -4x = 12 The only thing I can think of doing at this point is x - 2(x^(0.5)) = 12^(0.5) And that's kind of useless (i think). Any ideas?

Ahh, yes, I see. Defining "n" in this case as "the time, in years, it would take for the second amount to equal the first" would have circumvented this issue. Alternatively, if I were to use the book's method, "n" would be defined as: "the time, in years, it would take for the first amount to equal the second."

00 Ok, so here's the provided info: A person invests $10 000 @ 3% per annum Another person invests the same amount THREE YEARS LATER @ 5% per annum. When will they be equal? Here's the equation I came up with: 10 000 (1.03)^(n+3) = 10 000 (1.05)^(n) This yields an answer of ~4.61 Here is my work: 10 000 (1.03)^(n+3) = 10 000 (1.05)^(n) (n+3)log(1.03) = n(log(1.05)) n(log(1.03)) + 3(log(1.03)) = n(log(1.05)) 3(log(1.03)) = n(log(1.05)) - n(log(1.03)) 3(log(1.03)) = n(log1.05 - log1.03) n = ( 3log1.03 ) / ( log1.05 - log1.03) n = ~4.61 Here's the issue: The book uses the equation: 10 000 (1.03)^(n) = 10 000 (1.03)^(n-3) And here is the correct work and answer: n(log(1.03)) = (n-3)(log(1.05)) n(log1.03) = n(log1.05) - 3log(1.05) n(log1.03 - log1.05) = -3log(1.05) n = (-3log(1.05)) / (log1.03 - log1.05) n = ~7.61 This makes sense, as there are three less compounding periods (n-3) in the second (1.03%/annum) amount. Why, though, is this not the same exact thing as saying the first amount has (n+3) three more compounding periods? I understand that the maths yield a different answer, but would someone kindly conceptualy explain why the two are not equivilant?

for example... shrodinger's cat. when the lid is removed, the environment is no longer sealed. even in the absence of a measuring device, human EM radiation would collapse the wave function. same premise to explain the double slit experiment. i'm self-taught in physics, so i doubt this is the actual explanation. i just thought i'd throw it out there *awaiting nobel prize*

It is reported that the wave function will collapse when observed or due to environmental interaction. Is it possible that the wave function collapse in an experimental setting is due to electromagnetic interference from a human body?

What are the differences in function of the Trigeminal (V) and Facial (VII) Nerves?

Haha, thanks man. This is excellent. *bookmarked*

Thanks, SMF. This is a good summary. Does the connective tissue have a clinical name? One point of clarification, please. Was this a typo, or do these immune cells actually attract more connective tissue (resulting in tissue contraction/elevated levels of loose connective tissue available for waste/nutrient exchange)?

Thank you, that was a very well thought-out answer. *EDIT* I just noticed that you copy-pasta'd your reply from wikipedia without citing a source. For shame, sir. For shame. Are swelling, inflammation, and edema all the same thing?

Excuse my ignorance, I'm starting my adventure into pre-med next year, so this is my run-up to ensure my knowledge base is solid (meaning there will be more questions of this nature). =p Okay, so I understand the uvula has a function similar to that of the epiglottis (sp?) in closing access to airways during swallowing (whereas the epiglottis restricts access to the trachea, the uvula prevents food particles from traveling UPWARDS into nasal cavities). Is this correct? I was also wondering about the gag-reflex. Obviously coughing is a mechanism to remove foreign particles from the lungs and trachea, and sneezing removes them from the nasal cavities, but what function does gagging have? And why does the uvula have a touch sensitivity which results in the triggering of a gag reflex and possible expulsion of matter from the esophagus or stomach? In other words, what purpose does the sensitivity of the uvula serve? (also, does the uvula serve any other purposes? [excluding vocal manipulation] )

Can someone enlighten me as to the homeostatic purpose of inflammation? eg. muscle inflammation

well, M is the magnitude, the richter value the question was non-specific... so yeah. i assume its referring to intensity because the richter scale is an exponential function

Bah, I seem to have developed a mental block around logs... can someone tell me if this is right? M=magnitude I=Intensity U=Baseline (M = log (I/U) ) An earthquake registers 6.1 on the Richter Scale. What is the rating on a quake twice as powerful? My answer is : Let "M1" be the quake with a magnitude of 6.1. Let "M2" be the unknown quake magnitude. Let the intensity of M2 be called "I1" Let the intensity of the unknown quake be called "I2" (M1 = log (I/U) ) M1 = log (I/U) I/U = 10^(M1) I = ( 10^(M1) ) * (U) (I2/I1) = 2 The ratio of these two values must = 2 (for a quake twice as intense). (I2/I1) = (( 10^M2 )*( U )) / (( 10^M1 )*( U )) The baseline values ("U") divide out. (I2/I1) = (10^M2 ) / ( 10^M1 ) Substitute value for "M1" (I2/I1) = (10^M2 ) / ( 10^(6.1) ) (I2/I1) = 10^(M2 - 6.1) Substitute value for (I2/I1) 2 = 10^(M2 - 6.1) AKA (in common log form): M2 - 6.1 = log2 Calculator... ( M2 - 6.1 ) = 0.301029996 M2 = ( 0.301029996 + 6.1 ) M2 = 6.401029996 ~ to sig. digits M2 = 6.4 In retrospect I should've just found: 10^(x)=2 where: x=(M2-M1) I seem to be having trouble with logs. Does anyone have some tips to avoid over complicating these problems?

HAHAH wow. Um. **Fade Out***

Okay, erm, having some trouble. Here's the question: An investment pays 6%/annum Principle=$3000 Final=$6000 Time= (?) Here's what I keep getting, but something seems very, very wrong: F = P (1+i)^t $6000 = $3000 (1.06)^t $2000 = 1.06^t one way... t = log_1.06(2000) t = (log2000)/(log1.06) t = 130.445 another way... log2000 = log1.06^t log2000 = (t) log1.06 log2000/log1.06 = 130.445 What am I doing wrong here? There's no way it takes 130 years, 5 months, ~10 days, 4 hours, and 48 minutes to double an investment at 6%/annum.

Thx giaz oh, and i love you.

Heyo, Anyone aware of a calculator out there on the internet with capacity to calculate logarithms with non-common bases? i.e. log(base2)4(16^(1/3)) - log(base4)0.25^(1/3) = x Yes, yes, I know x=11/3 I just want a quick way to check my answers. Alternatively, is there a quick and easy way to convert non-common bases to common bases? (base10)

lol furry palms. and yes i know its in the wrong forum thats why i asked a mod to move it to the physiology forum...nothing yet tho... way to loaft, mods. *shakes fist at sky*

May be Cathaxanthin; sent emails to staff of Oprah requesting comformation. Status:pending Jan22/2011 Recently I saw an episode of Oprah in which Oprah claims a young white male consumed "life-threatening pills" in order to darken his skin. The result of this was said to be a reddish-brown pigmentation of the skin. A clip of the topic on the show: http://www.oprah.com/oprahshow/Black-for-a-Day-Video Your website also references the topic on these pages: http://www.oprah.com/oprahshow/Race-on-The-Oprah-Show-A-25-Year-Look-Back/print/1 http://www.oprah.com/oprahshow/Race-on-The-Oprah-Show-A-25-Year-Look-Back/5 This has been a source of interest to many people. Did Joshua consume Canthaxanthin? This would explain the "life-threatening" remark, as such medications remain unapproved by the FDA. I look forward to your reply, -Yoshi Yamagoto Notes: Cathaxanthin : http://en.wikipedia.org/wiki/Canthaxanthin -Brown-orange in color -Fat soluble -Attaches to sub dermal fat -Becomes more visible when fat is saturated -May cause liver damage -May cause yellow deposits in eyes -May cause rashes and hives

75 Views and No Replies?

SOURCE: OPRAH http://www.oprah.com/oprahshow/Race-on-The-Oprah-Show-A-25-Year-Look-Back/5 Okay, so this dude goes on Oprah awhile back, and claims that he took some "life threatening pills" to change his skin colour black. Is this even possible? It seems like horsecrap. He said his skin was reddish-brown. \ (Cite Sources Please)

This is true. A filter would be used to seperate solids and junk like that. What I'm after here is a feasible technique to turn vapours back into liquids or solids.

(Other than the exponent.) Anyone?

I'm also a smoker and got this idea as I watched the bottom of my cotton filter turn a steadily darker color Ah, but here's the catch - Some particles have been vapourized. Such as nicotine. Engineering a device to depose the vapour back into a solid (including minimal leftover nicotine from the secondhand smoke) seems to be possible via supercooling these vapour particles within a vacuum. I was wondering if there was an easier way to achieve this. I wasn't able to find any information on why brass would turn silver. My guess is that your mouthpiece is made of nickel with a brass coating (or laquer), or some type of brass/nickel alloy. This would work, but by this exercise I also hope to discover the measure of chemicals absorbed through the lungs per second. Obviously this will only focus on a few of the many chems within ciggys (ie. arsenic, CO, CO2, and nicotine). I hope to achieve this by first taking a control sample - the measure of chemicals emitted by a single cigarette at different stages of its burn cycle. The smoke will ideally be inhaled through various filters via suction. i. Samples with recirculation will be differentiated from those without in order to better measure the effects of smoking indoors vs outdoors. ii. (As a cigarette is inhaled, resin collects closer to the base of the cigarette, which, when smoked, tends to be stronger than the rest of the cigarette. Therefore, I hypothesize whether or not people finish entire cigarettes is indeed a factor in health applications.) Each sample will be collected for 60 seconds. This will make it easier to find how many chemicals have been deposed, per second.

Hey all, I want to collect, in a chamber of some sort, the secondhand smoke of many smokers. The goal of this is the deposition of most, if not all, chemicals and tar. How can this be readily achieved? (And yes, I have used google.) Are there certain substances that will not deposit? I'm not asking for a complete list, seeing as how there are myriad substances within cigarette smoke, but a few examples would be handy. Also, why would they not deposit? The goal is to render as pure of a deposit film as possible. Can this be achieved?