Recent content by JavierOlivares

I think I understand now. I was just confused on multiplying the X Matrix by another 2x2 Matrix. I was thinking the equations would combine X11 + X12 as in the case of a 2x2 and 2x1 but it makes sense now. Thanks.

I'm still a little confused. I understand that the matrix is symmetric. I just don't understand how they have it equal on the LHS a row of three 3x1 differential equations when K seems to be a 2x2. That's where I'm confused. I'm thinking this is some linear algebra property that's going over my...

https://www.physicsforums.com/attachments/upload_2016-11-26_20-39-19-png.109463/ I found a paper on this online that gives somewhat of an example of this problem. https://www.physicsforums.com/attachments/upload_2016-11-26_20-40-26-png.109465/...

Homework Statement I was wondering if I can get some help on a Linear Regulator Problem for an Optimal Control Problem. Given a state equation and performance measure I am trying to solve using the Riccati equation on MATLAB. This is a sample example I got from a book Optimal Control Donald...

Thanks for all the help. It makes a lot more sense now.

I guess I would have thought -(t - 1)*us(t - 1) would be the same as -t* us(t - 1) + 1*us(t - 1). I factored out -(t - 1). My question is why can't I just do that? I'll make up a different example to make sure I understand it. Let's say I had: (3t - 1)*us(t - 1) So I got to have (3t - 1) be the...

Okay thanks for clearing that up. I think that's where I keep messing up. The last post was my professors answer and yeah I got the right answer this time by following what you said. So I also get for : -2*us(t - 1) ↔ -2*e-2s/s I think that's what you mean right? The shifting property for f(t...

Our professor wanted us to do it with shifting rules and easy transforms for exams since integrating would take too long for more tedious problems. Sorry I should've mentioned that earlier. Thanks for the reply.

Attached

Homework Statement g(t) = (t+1)us(t) - (t-1)us(t-1) - 2us(t-1) - (t - 2)us(t-2) + (t-3)us)(t - 3) + us(t-3) Homework Equations unit step function us(t-3) is same as u3 (t) Shift in time: L[f(t - T)us(t-T)] = e-TsF(s) us(t) ↔ 1/s t ⇔ 1/s2 The Attempt at a Solution 1/s2 + 1/s - e-s/s2 + e-s/s -...

I got this formula from watching this video. Φ= (2π/λ)*Δx +ΔΦ0 where Δx = distance traveled from origin of both sources to some point. ΔΦ = inherent phase difference. I changed the first y1 equation into a sine equation. I now have: y1(t) = 3*sin(ωt +π/2 ) y2(t) = 3*sin(ωt + π/3) The inherent...

If I do what you said I get 30 degrees. Am I missing something?

Homework Statement Given two waves characterized by y1(t) = 3 cos wt; y2(t) = 3 sin(wt + 60deg); does y2(t) lead or lag y1(t) and by what phase angle? Homework Equations y1(t) = 3 cos wt; y2(t) = 3 sin(wt + 60deg) The formula I'm given in my book Fundamentals of Applied Electromagnetics is...

Hello. My name is Javier Olivares. I have been a lurker for sometime but decided to finally begin to be an active member. I really want to get some help/advice. I'm currently a junior at the University of Illinois at Chicago. I'm 26 years young where the VA covers my tuition from serving four...

Also note I already have a semester of BioEngineering done but switch so switching back would be a faster graduation rate.