Expression Definition and 999 Threads

http://img205.imageshack.us/img205/6923/logp.png What is the meaning of '+' above log? Is there an equivalent expression for this? Thanks

Homework Statement Obtain an expression for the rate (dV/dt) at which the voltage across a charging capacitor increases. Express your answer in terms of I, R, and C. 2. The attempt at a solution I found that at time=0, dV/dt=EMF/RC

Homework Statement I need to find an expression for the minimum drag coefficient, C_D, of an aircraft during straight and level flight. Homework Equations C_D=C_{D_0}+kC_L^2 Where: C_{D_0} is the profile drag coefficent C_L is the lift coefficient k is just a constant The Attempt at a...

Homework Statement Find an expression for the P-state lightwave of angular frequency w and amplitude E_0 propagating along a line in the xy-plane at 45 degrees to the x-axis and having its plane of vibration corresponding to the xy-plane. At t = 0, y = 0, and x = 0 the field is 0...

Homework Statement Hello, Can you help me to understand the question..Ineed clarification and hints to solve the question.. A circle and a square are to be constructed from a piece of a wire of length l. 1-give an expression for the total area of the square and circle formed...

nZ/mZ where / means a quotient group if n=1 then Z/mZ is the set of integers modulus n {0,1,2,3,4,...,n-1} in case m=2 we have a binary system, but i do not know what (1) will mean of ocurse 'Z' means the set of all (positive) integers.

\sum_{n=1}^{\infty}\frac{\ln n}{n}> \sum_{n=1}^{\infty}\frac{1}{n} ln is not always bigger then 1 so when i am doing the comparing test i can't use that because ln 1 =0 ??

Homework Statement csc(pi/2-x)/cos(x+pi/2) + cot(pi/2-x) The Attempt at a Solution 1/cosx/-sinx + sinx/cosx -1/sinxcosx+ sinx/cosx(sinx/sinx) (sin2x - 1) / sinxcosx -cos2x/sinxcosx -cosx/sinx -cotx is this right the answer key says it is cosx but that could be wrong I...

Homework Statement Find an equivalent expression for sin3x in terms of function values of x, 2x, 3x, raised only to the first power. The Attempt at a Solution stuck! don't know where to begin I am reviewing for my exam right now I remember doing one of these problems before but I can't...

Homework Statement cosx/(secx+tanx) The Attempt at a Solution So far I have this: =cosx/(1/cosx + sinx/cosx) =cosx/(sinx + 1/cosx) =cos2x/sinx + 1 From there I don't know what to do. I've messed around with it for a while but don't seem to get anywhere. Any help is appreciated.

i can take this down to

Homework Statement AN object moving along a curve in the xy-plane is at position (x(t),y(t)) at time t, where dx/dt=Arcsin(1-2*e^(-t)) and dy/dt= 4t/(1+t^3) for t>or= 0. At time t=2, the object is at the point (6,-3). a. Let m(t) denote the slope of the line tangent to the curve at...

So here is the problem, there is thin rod of length L with total charge Q. The rod was placed so it is along the y-axis. From the rod a distance x is point P Homework Statement Find an expression for the electric fields E at distance x from the end of the rod. Give your answer in component...

1. The problem statement, all variables and given/nknown data Find a formula for the expression. Use sigma notation. (x + 1/y)n The Attempt at a Solution Not sure how to do this we have only dealt with sigma notation involving only n as a variable

Homework Statement Derive an expression for the radius of a satellite's orbit around Earth in terms of the period of revolution, the universal gravitation constant, and Earth's mass. Homework Equations The final equation should be: r = \sqrt[3]{\frac{T^{2}Gm_{E}}{4\prod^{2}}} The...

I've done a calculus problem. The LHS is my answer and the RHS is the answer in the book. \frac{2(x-1)^2}{(x^2-1)^2} = \frac{2}{(x+1)^2} What was done to simplify this equation?

Homework Statement Rewrite the expression as a sum, difference or multiple of logs. log55x2 Homework Equations The Attempt at a Solution log55x2 = 2log55x = ...

Homework Statement Homework Equations Idk what to do after I multiply the LCD I get confused please help me. The Attempt at a Solution All I know is that the LCD is (x+5)(x+1)(x-2) and when I multiply into every fraction I get this. (X+5)(X-2)(X-2) - (X+5)(X+1)(X+1)...

Homework Statement In a system where other gravitational influences can be discounted, two particles of equall mass m, are fixed at positions x= 0 and x= x0 on the x-axis. 1) derive an expression for the gravitational potential Vgrav at a general position x on the x-axis.? Homework...

Homework Statement Use Euler's formula to write the given expression in the form a + ib: e^(2-(pi/2)i) Homework Equations Euler's formula: e^(it) = cos(t) + i*sin(t) The Attempt at a Solution I'm not sure how to get started on this one... am I supposed to get the expression into...

How, in general, do you "expand" an expression in powers of some variable? I'm studying mechanics right now out of the Landau-Lifschitz book, and he often talks about expanding expressions. But I honestly don't know how to do this, in general. I know about forming Taylor expansions of functions...

Homework Statement Find an expression for the electric potential a distance z away from the center of rod on the line that bisects the rod. Express your answer in term of k, Q, L, z and appropriate constants. Here is the picture. Homework Equations The Attempt at a...

I'm trying to find the quantity of energy transferred between two systems. I have an absorption curve and a drive curve, but neither of these follow a mathematical expression, they're random squiggely lines. I want to use the absorption curves to find out how much of the drive is being...

Homework Statement Prove that \displaystyle\sum_{x=2}^n \frac{1}{x^2}<\int_0^n \frac{1}{x^2} dx Homework Equations I'm not sure what equations are relevant for this, but I think for this I would need: \displaystyle\sum_{x}^{\infty} \frac{1}{x^s} =...

Homework Statement Knowing the given equations, k is equal to a measurement where J(t) implies some local coupling between the observer and observed system. If a field is considered to collapse J(t), how would the two manifest into a single expression. Homework Equations...

Homework Statement √8/3 Homework Equations none but there can't be any radicals in the denominator The Attempt at a Solution =√8/√3=2√2/√3... what do i do now.. I can't have a radical in the denominator

i need to prove that this expression is correct http://img216.imageshack.us/my.php?image=23051510gd6.gif f'(x)=d(f(x))/dx there is no such structure on the left side of the equation there are a defferential in the power of n only the d^n??

Homework Statement An object emitting light with a wavelength of L is traveling away from you with a relative speed of v, which is small compared to the speed of light. Write down the algebraic expression for the fractional change in wavelength between what you observe and what the object...

I am unable to simplify the tensor. I have the expression Bc.A(axb)+Bb.A(cxa)+Ba.A(bxc) In this capital letter is second order tensor and the small letter is vector.I have to simplify in the form like tr(Transpose(B)A)[a b c].Somebody can help me.

I am reading a paper that uses a quantum mechanical notation that I do not understand. I have found a webpage that explains it, but I do not understand the explanation either: http://chsfpc5.chem.ncsu.edu/~franzen/CH ... (let Y represent the Psi) Specifically, I understand what <Yn|A|Yn>...

Homework Statement IN * ((4x^5 - x -1)(square root x-7)) / (x^2 + 1)^3 The Attempt at a Solution in(4x^5 - x - 1) + in(square root x-7) - in(x^2 + 1)^3 in(4x^5 - x - 1) + 1/2in(x-7) - 3in(x^2 +1) 5in4x - inx - 1 + 1/2(inx -in7) - 3 (2inx + in) I know...

Homework Statement Prove that the expression \frac{a(a^2 + a)}{3} is an integer for all integers \geq 1 Homework Equations The Attempt at a Solution a(a^2 + a ) = 3q + r r can be: r = 0,1,2 for r = 0 \frac{a(a^2 + a)}{3} = q q is an integer by the division algorithm. When I...

Homework Statement A circular loop made from a flexible, conducting wire is shrinking. Its radius as a function of time is . The loop is perpendicular to a steady, uniform magnetic field B . Find an expression for the induced ε in the loop at time t. Give your answer in terms of , , t, B and...

Homework Statement 10P8 Homework Equations The Attempt at a Solution 2 1,814,400 3,628,800 80

\frac{1}{7} e^{-2t} \cos(4 \sqrt 6 t)+\frac{\sqrt 6}{21} e^{-2t} \sin(4 \sqrt 6 t) =\frac{\sqrt 15}{21} e^{-2t} \cos(4 \sqrt 6 t+\arctan \sqrt 6/2) I am having trouble figuring out how to prove this relation. Any help would be greatly appreciated. My initial thought was to use this...

I have been assigned a task that I have found to be very difficult - to try and develop an alaytical (mathematical) expression for the output voltage with respect to time of the cockroft-walton voltage doubler shown below (so that I can plot the transient response), when the input voltage is a...

Consider a simple alternating current generator such as Hippolyte Pixii's dynamo. The current generated by such dynamo can be described as simple oscillating cosine signal. Assuming for simplicity that the max current generated each time a pole of Pixii's magnet passed the coil is (2/pi)0.5...

Hello, firstly, what does the regular expression "\\+" do? Would that literally match up "\+". Could I possibly get some recommendations on some software to try regular expressions with as well actually please? and secondly, I've been fiddling around with the cacls command and I've noticed...

Homework Statement prove that 1!+2!+...+n! is not a square if n>=4 Homework Equations The Attempt at a Solution in the previous part I had to prove that a sqare cannot end in 2,3,7,8 and did this by working in mod10. Do you use this to prove the question? I have written n as 10q+r...

Homework Statement A wave source approaches you at constant speed and you measure a wave frequency f1. As the source passes and then recedes, you measure frequency f2. Find the expression for the frequency emitted if the source were stationary in terms of f1, f2, and wave speed v.Homework...

Homework Statement You have been asked to design a "ballistic spring system" to measure the speed of bullets. A spring whose spring constant is k is suspended from the ceiling. A block of mass M hangs from the spring. A bullet of mass m is fired vertically upward into the bottom of the...

Is there an algorithm for converting DFA (or NFA) into regular expressions?

Homework Statement Derive the error expression \delta v_{}x from the equation v _{x}=\frac{s}{sqrt(\frac{2h}{g})} The Attempt at a Solution I've derived error expressions before, but I have a history of getting the calculations right and the error equations wrong. So, if possible I'd...

Homework Statement Find the partial of z with respect to x keeping r constant. Homework Equations z=x2+y2 x= rcos(t) y= rsin(t) The Attempt at a Solution= r^2(cos(t))^2 + r^2(sin(t))^2 use product rule on "x" and hold r and y constant = [0(cos(t))^2 + r^2(2cos(t))(-sin(t)))] + 0...

I would like to solve 2^k = \frac{n}{k} for k in terms of n, but can't seem to do it. Any help greatly appreciated!

Homework Statement Consider the filling of a horizontal wedge-shape trough of height H, length, L, and width, B with water. (Imagine a water trough for horses with ends that are matching triangles). The volumetric flow rate of water in is given by Qi and the flow rate out by Qj. Obtain an...

Homework Statement psi(x,y)= Asin((ax^2)-(by^2)) Does this expression represent a traveling wave? If so what is the direction and speed of the wave? Homework Equations This wave resembles a a harmonic wave. psi(x,t)= Asin(kx-wt+phi) The Attempt at a Solution Ok, A,a,b are...

Homework Statement lim (1/sqrt(x+a)-1/sqrt x) x->0 Homework Equations None The Attempt at a Solution Too many too be listed :P

Homework Statement A block of mass M hangs from a uniform rope of length L and mass m. Find an expression for the tension in the rope as a function of the distance y measured vertically downward from the top of the rope. Homework Equations For the System: W = (m + M)g = T The...