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Hello Tom from EveryStepCalculus.com, EveryStepPhysics.com. A line integral problem again. I’m going to do this until I get done with the formulas that I’ve found so that you can do all these on your tests or whatever might come up on your test or homework . My programs are one-of-a-kind and the only one that does it. I’m not the only one they could do it but I’m the only one that does do it because I was into calculus at one time and then of course into programming which I like. Anyways you can go to my site buy my program for $40 and they’ll have you pass calculus, simple as that. And calculus I have determined is a worthless math concept, it doesn’t solve anything as far as I’m concerned. It can’t solve anything because it always comes up with one single number. It doesn’t come up with formulas or wild things that you can solve cancer with, or help with physical fitness and which they all say it does you know. But they’re just completely uninformed and and they don’t do this calculus as much as I do it. But anyways, index(8) to get to my menu, here’s a problem right off a test. Get to my main menu we’re gonna scroll down here I’m just gonna hold down on the cursor here to scroll down to the L section verse as line integrals. And choose that because that’s the subject we’re talking about. And here’s line integrals and we’re gonna do this, notice that these are all the possible test entries for line integrals, in other words you got dx dy, dx dy dz, function (x,y) a function of (x,y,z), and i j, and i j k and x equals okay? That’s what’s gonna be on any test you might take one of those. You have to choose which one. Now this one would be X Y Z they’ve left off the Y in here somewhere but you’ve got a Z here so you’re gonna choose, you certainly couldn’t do X Y. Choose number for X Y you’d have to choose number 5 X Y Z. So I’m going to press the number and scroll down or press the number. I’m gonna enter the function, now you’re gonna press alpha and enter this function here which is x squared times Z okay? Alpha X squared times z. Now I’ve already entered this in the these all these variables I’m not going to do each variable because I just wanted to show you how do you enter the variables in here. And, um, but I’ve entered them in here for speed you know. Now was given here as points you see points here? You know there’s segments that’s for sure they’re going from this point to this point, that’s a segment. So we choose points in my next menu and we’re going to X Y Z to X Y Z here’s X Y Z to X Y Z okay? So we’re going to choose that. I can’t put X 1 and X 2 etc because of the width of this screen here so I can, I have to keep it within the constraints of this area here. So you have to get used to my programs a little bit, try them out. Press number 3 and we’re gonna go quickly through entering these now you’d press alpha and put each one of these in. alpha 0 alpha 6l so alpha minus 1 and I show you what you’ve entered you can change it if you want I say it’s okay. And we’re gonna parameterize it okay? So and this is the formula, don’t let any professor tell you any different this is 1 minus T times the X 1 plus X 2 times T okay? That’s it, now you get all kinds of professors that throw this stuff around and these are the tough things you don’t know what they’re talking about, what they do, and they think it’s simple they’ve been, teaching this crap for years so they just you know throw it around but we have to know the formula and to be able to to make it couldn’t stream which with every other possible thing you know. And here’s y and here’s Z the parametrization of this okay? And when you parameterize the limits are zero the range is 0 to 1. So x equals 40 the derivative of that is 4 y equals 6 minus 5 T times T the derivative is minus 5 etc okay? Do it exactly like this system. ds right over here there’s a DS that equals the magnitude of the of this segment and that’s the derivative of RT which is these here X prime of Y squared and Y prime of square of Z prime of squared ok? 4 minus 5 6 does everything for you write this stuff down don’t even study it it’s not worth studying it’s a waste of time. so it ranges from zero here’s the integral here we were substituting all of those in for x and y here’s X and then of course we have the DS here okay? We bring all constants outside of the integral in calculus okay? If there’s a constant in here we bring it out. We integrate it, of course you could all integrate this like nothing couldn’t you? Of course you could. And then at T equals 1 we enter the T and in for all the t’s in this what we just found in the screen before we come 56 divided by 3 at T equals 0 we enter the zeros for all the t’s now comes 0 we always upper – lower in physics and in calculus 56 and 3-0 answers and then we add the the square root of 77 in your 57 56 you know this answer here okay? Notice that a line integral, notice how stupid everything is because this doesn’t even represent anything. What is this? feet? meters? is it square cube roots what is it? You never know just a bunch of garbage and go to my site buy my programs and pass calculus, believe me it’s the greatest programs ever, have a good one!