Reduction Definition and 472 Threads

Hey, guys. I'm having a hard time with a 2nd ODE reduction of order problem. The DE is t2y'' - 4ty' + 6y = 0, with y1 = t2. So I set up my y = t2v(t); y' = t2v' + 2tv; y'' = t2v'' + 4tv' + 2v. I then substituted back in and got: t4v'' = 0 This is where I'm getting stuck. The book...

Homework Statement x^2 y''+2xy'-12y=0,y_1=x^3 y''+(2y')/x-12y/x^2 =0 Homework Equations The Attempt at a Solution y=uy_1=ux y'=u' x+u y''=u'' x+2u' subbing that in instead of y,y',y'' u'' x+2u'+2(u'x+u)/x+12(ux)/x^2 =0 now my book says to reduce the...

Help! I'm a third-year chick in engineering, stuck on a block diagram reduction problem for my control systems engineering course. Please email me and I'll send you a screenshot of the problem! kati@sidwall.com Thanks a mill. K xo

"Photosystem I transfers electrons to NADP+, reducing it to NADPH." This is mentioned many times in my textbook, in other examples besides photosynthesis. NADP+ reduced into NADPH. I agree that receiving an electron is a reduction. But how does receiving electrons turn NADP+ to NADPH? That...

Define I(n) by I(n) = integral of x^n / square root(1+x^2) dx. Evaluate I(0), I(1) and then establish the reduction formula I(n) = ((root2)-(n-1)I(n-2))/(n) for suitable values of n, which should be stated Here is my attempt I found I(0) first,and got the answer to be...

Hi. Can someone help me please. I have a steam generator which is designed to operate from natural gas with pressure of 2000 -4000 mmAq. It consumes a volume of 71 Nm3/h of the gas. I want to operate it on Liquid Petroleum Gas (LPG-Propane). The problem is that LPG is available in cylinders at...

Hope I'm in the right spot, google searches lead me here. I am working with a couple N50 ring magnets which are axially magnetized, as an alternative to a coil spring. They are going around a steel rod which acts as the guide, and is an integral part of the complete assembly. My question...

In free field theory one particle states can be created as: |k\rangle =a^{\dag}(\vec{k})|0\rangle . Just as we can expand the field operator in terms of the creation and annihilation operators it is possible to obtain an expression for the creation operator in terms of the field, it turns out...

I have the following function to be reduced/simplified. F(A,B,C,D) = BC + (A + C'D') where ' denotes the complement Here's my solution: = BC + (A + C'D')' = BC + (A + (C+D) = BC + (A + C + D) = BC + C + A + D = C(B + 1) + A + D = C*1 + A + D = C + A + D Is this correct?

Homework Statement If we let A be the augmented m x (n + 1) matrix of a system of m linear equations with n unknowns Let B be the m x n matrix obtained from A by removing the last column. Let C be the matrix in row reduced form obtained from A by elementary row operations...

Hi all, I am conducting some tests on a simulated physical model of a motor/drive axle system. The goal of the experimentation is to come up with some suggestions to reduce the peak magnitude at the resonant frequency by 30%. Based on the analysis done, a few proposed changes are 1)...

Homework Statement I am having trouble row reducing... 5cos(t) 5sin(t) | -cos(t) 2cos(t)+sin(t) 2sin(t)-cos(t) | sin(t) Homework Equations The Attempt at a Solution I know I am allowed to multiply a row by a constant but I...

How exactly do you decide which operations to do in doing a matrix row reduction? Every example I see just randomly multiplies the rows or does row operations and magically they get the answer. HOW do you know to do certain operations? I understand the reduced row echelon form but it still...

I have trouble solving the following question, would someone offer some help? thanks. In very dry regions, the phenomenon called Virga is very important because it can endanger aeroplanes. [See Wikipedia] Virga is rain in air that is so dry that the raindrops evaporate before they can...

Hello :smile: I was hoping someone could help me with this. I'm going round in circles and don't understand how to solve it. Homework Statement The integral I_m is defined as: I_m = \int^{\frac{\pi}{2}} _{0} (cos^m(x))dx where m is a positive integer. By representing cos^m(x)...

Homework Statement Which of the following statements is correct if Standard reduction potentials of Cu and Sn are 0.337V and -0.136V resp. (both from +2 charge) a) Cu2+ ions can be reduced by H2(g) b) Cu can be oxidised by H+ c) Sn2+ ions can be oxidised by H2(g) d) Cu can reduce Sn2+...

Can anyone help me out with a proof for the integral that's in the attached images, its driving me nuts :frown:

Homework Statement Can you do integral of sec^5(x)tan^2(x) without reduction formula? Homework Equations The Attempt at a Solution If so, would it be integration by parts? I tried splitting it up in way too many ways to post them on here. Thanks for any hints!

Homework Statement A man stands 3m from a siren. How far does he have to move to reduce the intensity level by 20 decibels? Homework Equations Intensity level = 10log(I/Io) the inverse square law The Attempt at a Solution i know the answer is 30m because 10 times the distance drops...

Hi, I know that massive field theories are not conformally invariant. However one can incorporate mass by adding an extra dimension, and setting its corresponding momentum to be equal to mass and thereby modifying the constraint equation for spin. The next step as I understand is to perform...

Homework Statement derive a reduction formula for ∫(lnx)n dx and use it to evaluate ∫1e (lnx)3dx Homework Equations The Attempt at a Solution In other examples we've started by saying ∫(lnx)ndx = ∫(lnx)(lnx)n-1dx and using integration by parts. So let: f = (lnx)n-1 f' =...

Legendre's eq of order n>=0 is (1-x^2)y'' -2xy' +n(n+1)y = 0. You are given the soln y = P_n(x) for n=0,1,2,3 to be P_0(x)=1 ; P_1(x)=x ; P_2(x)=(3x^2-1)/2 ; P_3(x)=(5x^3 -3x)/2. Use reduction of order to find the second independent soln's Q_n(x) OK I've found Q_1(x) = ln(1-x)(1+x)...

Hello everyone, Ok generally what do they mean when they say vasodilation in periphery lead to reduction in blood pressure? Do I have to think of this as expanding the size of a fluid filled container so less fluid splashes againts the walls reducing pressure. Or do I have to think of this...

Homework Statement Reduce the given ellipse in standard form and find its centre and eccentricity. 4(x-2y+1)2 + 9(2x+y+2)2 = 25 Homework Equations Rotation of axes x=Xcosθ - Ysinθ y=Xsinθ + Ycosθ

Homework Statement y'' +(y')^2 = 6(y') -9 Homework Equations u = y' u' = y'' The Attempt at a Solution equation from 1 becomes u' + U^2 = 6u - 9 du/dx + u ^2 = 6u-9 du/dx = -u^2 + 6u -9 du/dx = -(u^2 +6u - 9) du/dx = -(u-3)^2 du/(u-3)^2 = - dx integrate...

found this on this page http://www.chemguide.co.uk/mechanisms/nucadd/reduce.html#top can someone explain why it is simplified? and how does it really happen?

Interesting paper: http://arxiv.org/abs/1009.1136v1 The Small Scale Structure of Spacetime Steven Carlip (Submitted on 6 Sep 2010) Abstract: Several lines of evidence hint that quantum gravity at very small distances may be effectively two-dimensional. I summarize the evidence for such...

Carlip has argued that the dimensional reduction in many apprroaches to quantum gravity is related to the BKL limit where the dynamics becomes 1D, and the spectral dimension becomes 2D. http://arxiv.org/abs/0909.3329 Interestingly, another viewpoint about the (de)-emergence of space comes...

I have a homework problem where I am to find y_2 for a 2nd ODE, with y_1=x. I'm familiar with the process of: let y_2 = ux y_2- = u'x u y_2'' = 2u' + u''x substituting these terms into the 2ODE, then letting u' = v. When integrating v and u' to solve for u, do I need to include...

Homework Statement solve y"-4y'+4y=0 y1=e^(2x) using reduction of order The Attempt at a Solution y2=uy=ue^2x y2'=u'e^2x+2ue^2x y2"=u"e^2x+4u'e^2x+4ue^2x I then substitute that into the original equation to get u"e^2x+4u'e^2x+4ue^2x-4u'e^2x-8ue^2x+ue^2x=0 simplify to get...

Homework Statement find the first and second derivative of first solution. Homework Equations y(x)=m(x)y_1(x) y'(x)=m'(x)y_1(x)+m(x)y_1'(x) The Attempt at a Solution I have been given y_1=\frac{1}{x^n} Which part is the m(x) and which is y_1(x) I'm not sure how to do...

Hi When you are reducing benzophenone to diphenylethanol you use 4 moles of sodium borohydride. I don't know how you would write this as an equation because I don't know what the sodium borohydride becomes. It has lost 4 hydride ions and is just with a sodium and boron. Also, you haven't made...

Homework Statement Use the substitution y = (x^2 + 1)u to solve the differential equation (x^2 +1)y\prime\prime = 2y The Attempt at a Solution I was having some trouble with these earlier because I needed to brush up on my trigonometric substitution. Let's try this one... Making the...

I have some difficulties on calculating the reduction on cold rolling process but mi signs is negative. Is that normal? Cheers

Hi 1 ) show how many electron are transferred in the following equation a ) Cu + Ag ----- > Cu^+ + Ag B) Zn + cl2 ----- > ZnCl2 my answer is : A) Cu ---- > Cu ^+ + ie- 1e + Ag^+ ----- > Ag then the electron which transfer is ( 1 ) B ) Zn + cl2 ---- zncl2 Zn...

find the general solution of (cos x)y''-y'+y = 0 L[y1] = 0 L[y2] = 0 L[y1] x y2 : (cos x)y1'' y2 - y1'y2 + y1y2 = 0 ...(i) L[y2] x y1 : (cos x)y2'' y1 - y2'y1 + y1y2 = 0 ...(ii) (i) -(ii) : (cos x)(y2''y1 - y1''y2) - (y2'y1 - y1'y2) = 0 W = | y1 y2 | = y1y2' - y2y1' | y1' y2'| W' =...

Like entropy tends towards chaos, why do star systems or galaxies tend to reduce their movement through the 3rd "Z" dimension even though all particles can freely move in all 3 dimensions? Flattening out. Is there some sort of word or phrase which describes this behavior? Is it possible...

Homework Statement Well, I've been doing a lot of research about the reduction formula as a method for resolving integration problems. However, not much information on the topic is to be found about the topic. The only things i get to find are examples with the formulas already given, which is...

Homework Statement Let I_{n} = \int^{2}_{0} x^{n}e^{x} dx where n is a positive integer. Use integration by parts to show that 2^{n}e^{2} - nI_{n-1} By first finding I_{1} = \int ^{2}_{0} xe^{x} dx find I2 and I3.Homework Equations I'm sure your all aware of the formula for Int by...

Homework Statement Solve: y'' -y' e^{y'^2-y^2} = 0 y(0) = 1 y'(0) = 0 Homework Equations The Attempt at a Solution No idea how to use it. If I use the substituion y' = p, and y'' = p'p I need to integrate e^{y^2} which is unintegratable. What should I do?

1. Homework Statement : It can be shown that for a uniform sphere the force of gravity at a point inside the sphere depends only on the mass closer to the center than that point. The net force of gravity due to points outside the radius of the point cancels. Question: How far would you have...

Homework Statement http://img708.imageshack.us/img708/7309/10324398.jpg The Attempt at a Solution First I row reduced the matrix into the RREF and got \left[ \begin{array}{cccc} 1 & 0 & -1 & -2 \\ 0 & 1 & 2 & 3 \\ 0 & 0 & 0 & 0 \end{array} \right] (0,1,2,3) is a linear...

[b]1. When you buy earplugs at the store, they have a "dB rating". What it tells you is the reduction of SIL that the plugs will provide, if properly worn. Suppose you're helping some friends, working the stage at a rock concert wearing earplugs that provide a reduction of 40 dB. What is the...

Why do you have to add sodium borohydride slowly to reduce benzophenone to benzhydrol? And why do we have to place the reaction in iced water?

Homework Statement Reduce 34567 modulo 19. Homework Equations The Attempt at a Solution I approached by first reducing 4567 modulo 18. I got the following: 34567= 318*253+13=(318)253*313 congruent to 12531594323 congruent to 14 mod 19 Is this the correct approach? I am not...

I plan on using two solar cells that can each generate 3 volts and ~80mA each and wiring them in series to get an array that generates 6 volts and ~80mA. However, I need ~4.5 volts from the array. What would be the best way to decrease the voltage to this level with the given array?

You dig a hole half way to the center of the earth. You lower an object to the bottom of the hole. By what fraction has the force of the Earth’s gravity on the object been reduced relative to that at the surface? Assume that the Earth is a sphere and has uniform density

Hey guys, I'm stuck on this problem! I have no idea how to even go about solving it. I tried searching the net for D'Alembert's principle but nothing was helpful. Any suggestions on how to go about solving it will be much appreciated! Find with the aid of D’Alembert’s reduction principle the...

I have been stumped by a simplification problem - well, I can solve it, but I'm not sure how to do it axiomatically! The expression is A(B+C)+B'D+C'D' I can see that the (B+C) is redundant in the first term - if A is true, the whole is true regardless of (B+C)'s value. So it reduces to...

The two commercial methods of reducing ZnO to Zn appear to be Thermal, in the presence of C: 2 ZnO + C → 2 Zn + CO2 and electrowinning: ZnO + H2SO4 → ZnSO4 + H2O (followed by electrolysis on the ZnSO4) But what is the effect of straight electrolysis on ZnO in the presence of some electrolyte to...