Log Definition and 618 Threads

I have a lot of Excel spreadsheets which are actually log files from a test (so they all have the same structure) and I need to get the data (a number) from a specific cell (same cell) in each file and do their average. Does anybody know an efficient method to do this?

Homework Statement Two rivers of unequal width (64m and 125m) meet at a right angle, forming an L-shaped channel. What is the longest possible log you can float on it? Homework Equations The Attempt at a Solution I tried for equal widths and built a recursive algorithm for turning...

Can someone help me use L'HOP to determine lim x -> 0 [ \sqrt{x}*ln(x) ] ? I'm confused!

Can someone explain to me why the graph of: logy=logx² is the graph of a regular parabola logy=2logx is the graph of half a parabola (x>0) logxy=2 is the graph of half a parabola except x>0 and x cannot be equal to 1 I just don't understand why they're not all normal parabolas, and...

Integrating Natural Log Function using "Integration by Parts" Method Homework Statement The problem says to integrate ln(2x+1)dx Homework Equations I used u=ln(2x+1); du = 2dx/(2x+1); dv=dx; v=x The Attempt at a Solution So, I integrated it using that (above) 'dictionary' and I...

Hello: I seem to recall a vague truth that a^(log n) = n ^ (log a)? Can someone verify? Thanks.

Hello, I have a column of 'x' values, each with an error 'err_x' serving as error bars. My question is: If I need to plot 'log(x)', Do I need to make any changes to 'err_x' to reflect the log operation before plotting them as error bars ? Thank you in advance Lorna

Homework Statement F(x) = (8-12ln|x|)/(x^4) > 0 (a) For what values of x is the expression F(x) defined? Write your answer in interval notation. (b) At what value(s) of x is the expression F(x) equal to zero? If there is more than one answer separate them by commas. (c) The set of...

Homework Statement f(x) = log2 x + 3 2 log2 x − 1 how do i find the inverse of this? how do i find the range and domain of a log function? Homework Equationsf(x) = log2 x + 3 2 log2 x − 1 is equal to f(x) = log2 x + 3 - log2 (x − 1)2 D of f(x) = R of f-1(x) The...

Is there a way to calculate multi digit base 10 logs without a calc or tables? eg.. what is ? log (base 10) of 1381.42?? (without a calulator)??

A second 0.63 bullfrog is on a log tilted 33 above horizontal. How large is the normal force of the log on this bullfrog?

Integrate the function. (3x)/(3x-2) I am spose to use integration by parts but i don't know how to integrate 1/(3x-2). anybody help??

Would it be okay to redefine the complex definition of Log and define it for example C\[0,infinity)? I guess then you would have Log z = log |z| + i Arg(z) where -Pi<=Arg(z)<Pi Everything would work fine? But then you can't have Log 5 for example which would be very counter unintuitive.

I hit the submit instead of the preview. please wait Homework Statement \int9s9^s dsHomework Equations ∫udv=uv-∫9^sds-∫vduThe Attempt at a Solution u=9s du=9ds dv=9^s ds v=∫9^sds =∫3^(2s) ds =3^(2s)/[2ln(3)] this is as far as i have gotten. Am i correct so far?

how the heck do you simplify this ? (Ln (2x/y) / Ln (x/y)) = m/n HELP ME!

ive got integral[(2/(2-z))+(2/(1+2z))]dz=integral dv/v then the next line is ln|v|=-2ln|2-z|+ln|1+2z|+c when i equate this i get rid of the 2 as a common factor integrate the V side first and multiply through by 1/2 giving me ln|2-z|+ln|1+2z|=1/2ln|v| which i don't think is the same as...

I'm having trouble on these two problems. Can anyone give me a step by step explanation on how to do them (or one of them)? 7. Find f'(x), if f(x) = \left|\frac {x^2\left((3x + 2)^{\frac {1}{3}}\right)}{(2x - 3)^3}\right| 13. Perform the integration: (a) \int(x-1)e^{-x^2+2x}dx (b)...

I know that logarithms to the base 1 is undefined, due to the reason that: \log_1{x} = \frac{\log_a{x}}{\log_a{1}} And this leads to divison by zero, which is undefined. There was a question in one of my textbooks that asked describe the graph that results if y = \log_1{x}. Is such a graph...

I am starting my first year of college and I reviewing my high school notes from trig pre-cal and there was one thing I couldn't figure out. It was a multiple choice question and I don't have the textbook anymore but the answer I circled I can't understand how I arrived to that answer...

Homework Statement sqrt(ln(x)) = ln(sqrt(x)) Homework Equations The Attempt at a Solution I've been trying to do this for some time now. Could anyone give some tips on how to get started with this?

1. Given Y = ln [ (x+1)^3/((x^2)-1)^(1/2), find y' 2. I came out with the following answer to this question: (3x-4)/((x^2)-1) How ever, I typed the question into an online derivative calculator (to hopefully check my asnwer as I have no answer key, and want to make sure I'm on the...

1. Given Y = ln [ (x+1)^3/((x^2)-1)^(1/2), find y' 2. I came out with the following answer to this question: (3x-4)/((x^2)-1) How ever, I typed the question into an online derivative calculator (to hopefully check my asnwer as I have no answer key, and want to make sure I'm on the...

I am glad I never created an account on youtube. I do not use it much. Viacom will not be able to know which video I have been watching. I wonder, once they found you watch copyrighted material every day, what will they do about it ?

Homework Statement Given that log_{2}x = p a) Find log_{2}8x^{2} in terms of p The Attempt at a Solution take the power outside the log 2log_{2}8x but i can't see what to do next Any suggestions Thanks :)

Is it true that e^{2(2x+ln2)} = e^{4x}e^{2ln2} I can't see how that is true? According to a paper mark scheme it is. Can someone clarify Thanks :)

Homework Statement The function f(x) =ln(10 - x) is represented as a power series in the form f(x) = (sum from 0 to infinity) of c_{n}x^{n} Find the first few coefficients in the power series. The Attempt at a Solution I know how to find the coefficients in a normal looking...

how do logs work when it's like this. 3 log10 y = -2 log10 y = a 10^a = y so it's 10^-2 = y but where does the 3 go, and why does it go there. I'm not sure.

i need help with this: lim x->\infty of \frac{ln(2+h) - ln(2)}{h} i have no idea where to even begin! i tried resolving it, but it didn't help :[ any suggestions??

hi, I'm new around here but i really need your help this question is similar to one already solved here some years ago so my problem is: 1.The vapour pressure of benzene between 10°C and 30°C fits the expression log(p/Torr) = 7.960 - 1780/(T/K). Calculate (a) the enthalpy of...

Hey folks, I'm reading the paper: http://arxiv.org/abs/hep-ph/0301168 and I'm trying to make sense of the first line of eqtn 44 where he states that we can write: \frac{1}{2}\sum \int\frac{d^{2n}k}{(2\pi)^{2n}}log(k^2+\frac{m^2}{L^2}) as...

I am a new user of Mathematica software, and need to plot a quite complicate function using a semi-Log type plot. The function that the software provides is LogPlot however this function plots the Y axis in Log scale and the X in linear scale, but I need the exact opposite, to plot the X axis in...

I don't know how I managed to forget this one, but I did somehow... If there's something like: e^lnx, why is that equal to just x? and same goes for sokmething like: 8^log[SIZE="1"]8x which is just equal to x. I'm just wondering how, algebraically, one could show this to be true.

Let X and Y be random variables. X ~ N(u,s^2) Y = r ln X, where r is a constant. What is the distribution of Y? (This is not a homework problem. It's just related to something I was curious about, and I can't figure out how to solve this, if it is solvable...)

Homework Statement Solve for "x" in the equation: ln(x+2)-ln(x+3)+ln(x)=1 The Attempt at a Solution This unusual ln problem really has me stumped with what to do and usually this stuff has given me no problems. I can't isolate the x because e is always in the way of solving it...

Homework Statement Simplify fully: log a + log b – log b^2 The Attempt at a Solution I don't even know where to start...

y''-y'-30y=ln(t) My attempt: i tried to use the method of undetermined coefficients. y''-y'-30y=ln(t) Y(t)=A lnt Y'(t)=A/t Y''(t)= -A/t^2 I also tried: Y(t) = A ln(t) + B 1/t + C 1/t^2 now I am stuck...any help??

Not so much a question query here but a query about how my question is written. Im having to do some integration and my question has one part loge (log sub e). I think that this is just natural log which i usually see written as ln(x). Is this correct? However my table of integrals has...

Has anyone seen this identity: g^{ab}\nabla g_{ab}=\nabla ln|g| I've seen it used, but want to figure out where it comes from. Does anyone know a name or have any ideas??

A rope is tied to a 97.8 kg log. When you pull on the rope with a horizontal force of magnitude 706 N, the log moves at constant speed. a) Find the magnitude of the resistive (frictional) force acting on the log. You may assume the frictional forces acting on the log is constant. N b)...

Hello, I am interested in the average behaviour of the log of a function. I know the average of the function over the range of interest: F = \frac{1}{(b-a)} \int_a^b f(x) dx. I also know that f(x) is convex and bounded from below by 1. I want to know the average \frac{1}{(b-a)}...

Question asked to find the units of k after you find the porpotionality statement i ended up getting t\propto\frac{\sqrt{h}}{d^2} so i turned that into an equation and end up with t=k\frac{\sqrt{h}}{d^2} solved for and found it on average to be 30 now the question is asking what the...

Homework Statement Find the limit of (tanx)^cosx as x-->infinity Rearrange the equation so that you can use L'Hopital's rule for the form of (infinity/infinity) The Attempt at a Solution I did ln(tanx)^cosx = cosxlntanx I know the limit of tanx as x-->infinity is pi/2 the limit of cosx as...

I've got a simple question that's been bugging me for a while. I think I know where the problem is, I'd just like a formal mathematical reason why I can't say this: \ln{(-1)}^2 = \ln(1) = 0 That part is fine...but then: \ln{(-1)}^2 = 2 \ln(-1) = 2 (i \pi) when they should...

[SOLVED] Help a newbie! Hey everyone. This will be my first post. A little background info: I have a bit of math anxiety due to doing very poorly with it in school despite a bit of effort. I had finished college in May with a degree that required only Statistics. My last year, I had...

Homework Statement See image Homework Equations M = log(I_i / I_o) The Attempt at a Solution See image

Roshambo is the name for a popular two-person hand game. It may also be referred to as Paper, Rock, Scissors. Rock blunts scissors, scissors cut paper, paper folds around rock. Nature plays it too. But instead of paper it uses logs: Log folds around rock...

Homework Statement Let f be the function given by f(x) = ln [ x/ (x-1)] (a) What is the domain of f? (b) What is the value of the derivative of f at x = -1. (c) Write an expression for f^(-1) of x, where f^(-1) denotes the inverse function of f. The Attempt at a Solution a. x / x-1...

Homework Statement A hearing aid increases the sound intensity level, thereby allowing a person to hear better. For the following decibel increases, by how much does the intensity of sound increase? a)30dB b) 22dB Homework Equations \beta=10log (I/Io)The Attempt at a Solution I substitute...

can someone please explain this to me?

Homework Statement Solve the equation log base 7 (7x+8) = log base 7 (7x+3) Homework Equations I don't think you use equations for this, just the properties of logarithms The Attempt at a Solution I thought since they have the same base you could set the parts in parenthesis equal to each...