Recent content by cameuth

No, I'm trying to approximate this differential equation using the runge-kutta method, then plot the error. But, I can't really do any of that without the proper differential equation. Which is where I'm stuck.

THE PROBLEM : y(t) = e^(-t)*sin(t^2); with t0 = 0 and T = 3.14159. Find y_0, and use it to deduce the corresponding expression for f(t, y) (Your f should have both a t and a y in it. Simplify it to find the y!). This is for a MATLAB project. I've solved this differential equation (which we...

Thanks. I'm an idiot. I knew it was something simple.

Ok, so I know this shouldn't be so hard. I am trying to convert a Coefficient of thermal expansion from 7.78E-6k^-1 to C^-1. But, I'm not sure what the conversion rate would be in this case. This is an odd conversion because you add to switch between C and K. So I'm not sure how to convert these...

Homework Statement Suppose that the weights of airline passenger bags are normally distributed with a mean of 48.14 pounds and a standard deviation of 3.71 pounds. Let X represent the weight of a randomly selected bag. For what value of c is P(E(X) - c < X < E(X) + c)=0.95? Give your answer...

Homework Statement solve the differential equation: (1+t^2)y'+4ty=(1+t^2)^-2Homework Equations μ=exp∫adt The Attempt at a Solution this problem gets quite ugly, so here goes. first question does μ=e^(1+t^2)^2

thanks. vela helped, and saladsamurai's elaboration was necessary. You guys are lifesavers.

Homework Statement integrate .5e^(t/50)*sin(t) Homework Equations integration by parts uv-∫vduThe Attempt at a Solution I am currently in differential equations and I remember from cal II that I have to keep using the equation above until the integral loops around, then set it equal to...

It's an upper level engineering class, but it's also a basic materials class. Basically, a lot is expected of us, so I want to be sure that I'm not missing some simple proof. If that were the case, I'd receive little to no credit for my answer.

alright guys, I've been trying to tackle this for a couple of hours now. dy/dt-2y=4-t my integrating factor is e^(-2t) of course. dy(e^(-2t))/dt-2ye^(-2t)=4e^(-2t)-te^(-2t) then I get completely lost. how do I integrate when it's like this? My book simplifies the above equation into...

I suppose I wouldn't have to prove it using math, but I do feel like I need some reason other than "they look perpendicular". I guess the reasoning behind why this happens is what I'm after.

Homework Statement do you notice a relationship between the plane and directions of the same miller index? what is it? Homework Equations I've done planes and directions (111), [111], (112), and [112] The Attempt at a Solution I believe the direction is normal to the plane on first...

sorry for the late reply. I got the answer guys, and y'all were a ton of help. Seriously, thanks. It's been awhile since six months since I've done cal 3 and so my integrating has some rust to knock off.

I'm sorry... but can you explain why that is. Intuitively what I see is dy/dt=5-y divide by (5-y) multiply by dt dy/5-y=dt I'm sorry again that I'm such a beginner at this, I just don't understand why you did what you did. I see that it gets me the right answer your way, but not why we go...

OK, so clearly I am missing something, because I know this is supposed to be a simple problem. It reads: solve the following initial value problem: dy/dt=-y+5 y(0)=y_naught my process is as follows: dy/(5-y)=dt integrate ln(5-y)=t+C exponential both sides 5-y=(e^t)(e^c)...