Recent content by Nauraushaun

I'm not sure about the definitions! Therein lies the problem :D Well, it depends how you interpret it. It's got the X axis, which could be seen as 0. On a Voltage vs. time graph, both maximums and minimums are 'high' points of voltage, so this could be the same. On the other hand, the notion of...

Homework Statement Well it's not so much a direct question as it is several. I'm very confused about sound waves. I know that, when modeled as a transverse wave on a set of axis, a compression is a maximum and a rarefaction is a minimum. But where do nodes and antinodes fit into this? Which...

Yeah but not where I've expressed interest. Maths may pop up, but I don't expect it to, and I'm reasonably well prepared either way. :D

I honestly don't have the time, and I probably won't do this kind of maths ever again after this year. I'm hunting for a high score for my last year of school, but that's all really, I'm planning a career in IT. And you're right, it probably is lack of experience. But I have a book of notes I...

Ah yes. I grasped that rule a long time ago. But, what I do, I have trouble applying rules to everything. Not trouble as such, but sometimes I just forget that rules apply in certain situations and get messed up, until someone like you shows me the light. But yeah you're right, I was doing it...

Well I figured the square root of 50^2 was 50...Right?

Oh nevermind, I got a friend from school to help me. I'd gone down the wrong path, what I had up there in my previous post is what I should've been differentiating. That's what I did, I obtained x = 28.46. Thanks very much Borek and HallsofIvy for your help :D

Well, I had c^2=(120-x)^2+50^2, and, to get c= I square rooted the righthand site. Maybe I should've left it how it was, with the root sign over it, rather than actually square rooting it.

Oops. I already did check my math, and edited. Turns out, after a recheck, I was wrong again. =(1235000-137655x)+(564000-4700x) =1799000-142355x Now what. Jeez I hope that's right.

Okay then. Well I've got Cost=134799000-132955x. Obtained from (130-14.49x)*9500 + (120-x)*4700. And again, I'm not sure where to go next.

I was tired, that's how. Ah, I see what I did. When I have brackets squared, I tend to just square the insides, rather than expanding and simplifying like I should. If you've gotten to the stage where c^2= x^2-240x+16900, shouldn't you find the square root of the numbers right of the = sign...

Okay, I've got the distance from A to the beach as 130-x. But it doesn't seem right, I'll need to differentiate at some point to get a minimum. I got it by using pythagoras on (120-x)^2+50^2... Could you tell me if I'm on the right path or not? I need to head to bed, I wanted to have a crack...

:O! Thank you very much. I'll work on it and get back to you.

I'm not exactly sure, as I just don't know how to do it, but it probably concerns finding a formula to describe cost, then finding dy/dx = 0 to find the minimum. The reason I've shown no working is that I don't know where to start exactly. If I could find a formula I'm sure I could do the rest...

So if I use either of those formulas... I = C*(dV/dt) I = 10*(5/1) I = 50 I get 50, mA I presume. But how did they get -100 as well, and the graph they've got?