Recent content by theclock54

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    Cost of Manufacturing X Items (average cost minimization)

    Homework Statement If the cost of manufacturing x items is: C(x) = (x^3)+21(x^2)+110x+20 Homework Equations All right, so the first few questions asked for total cost of producing 100 items, and marginal cost. I understood those well. Then it asked for the average cost function...
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    Failing at Calculus: Struggling with Exams and Seeking Advice

    There's always times in my Calculus 1 class where I am completely lost, and just basically copying down what the professor writes, even though I don't understand any of it. The thing that helps me is doing extra homework, my class has to homework online, and submit it with a paper copy. So what...
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    At what age can you tell if you're good at math?

    Everyone learns differently. I never tried in high school, I passed first semester Algebra 2 with a C, and failed the next semester. But, I got serious and took Trig during college, and Pre/Cal (which I thought would be brutal but wasn't) over the summer. Now I'm in Calculus and learning a lot...
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    Understanding the Limit of sqrt(x^2 + 2x -1) + x as x Approaches -infinity

    If we were to approach positive infinity, that would mean the x's are all approaching a positive number. But the thing is when I put the x in the square root, I square it right? And if I'm approaching negative infinity, the negative just disappears because it's squared. So we must put a negative...
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    Understanding the Limit of sqrt(x^2 + 2x -1) + x as x Approaches -infinity

    this is still the limit section, i doubt he knows what l'hopitals rule is. neither do i
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    Understanding the Limit of sqrt(x^2 + 2x -1) + x as x Approaches -infinity

    All right, notice that you can multiply by the conjugate. So that's what we do. In essence we're multiplying by one. We multiply the top and bottom by: square root ((x^2)+2x-1)-x / (x^2)+2x-1)-x notice it's minus x, that's the conjugate. then when you simplify it you get (2x-1)/(square...
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    Finding Inverse of f(x)=3x+5/x-4

    *sorry I forgot to put the negative sign on 5...it should be (-5-4x)/(3-x) = y
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    Finding Inverse of f(x)=3x+5/x-4

    Okay so first you switch the x's and y's. Then you'll have: x= (3y+5)/(y-4) Let's multiply by y-4 which leaves... xy-4x = 3y+5 when you want to solve for a variable and there's two of them, you want to get them on the same side and factor it out. so now what you do is subtract...
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    Do you know of any audio Calculus lectures and/or review?

    Yeah I've checked OCW, they just have the videos. Lol, yeah I usually do that also. But you still picture everything they do, even though you're not watching the video lol.
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    Projects/activities for someone who is interested in electrical engineering?

    I'm interested in going into the field of Electrical Engineering, but still have around 1 or 2 years. What are some activities/projects I can do to get my feet wet with electrical engineering? Any advice, tips would be greatly appreciated. Just something to get me started, and to keep me...
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    Do you know of any audio Calculus lectures and/or review?

    I'm doing well in my Calculus course, but I drive 15 minutes to get to class and back. I really think I should utilize this time. Can anyone recommend any lectures I can listen to while driving? I'm sure it can also really help get the concepts down. Anything would be helpful. Thank you in...
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    Tangent line to the curve f(x)= x + 1/x

    Ohh, I was trying to add up all the fractions first. I didn't even notice the x's canceled out. Okay, so when I subtract 1/x+h - 1/x I get -h/x+h After the mess, I get my answer to be (h+x-1)/x+h
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    Tangent line to the curve f(x)= x + 1/x

    @gb7nash Okay, so now I have: [x^2+2xh+h^2+1]/(x+h) - (x^2+1)/x Get another com. denom then I have: [x(x^2+2xh+h^2+1) - (x^2+1)] / x(x+h)
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    Tangent line to the curve f(x)= x + 1/x

    Yeah we're on derivatives, I just forgot to put the whole equation over h. @gb7nash That's where I'm stuck, when find a common denominator and subtract both equations, the h doesn't cancel out. So I'm doing something wrong. When I add the x+h and 1/x+h, I get [(x+h)^2 + 1]/(x+h) -...
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    Tangent line to the curve f(x)= x + 1/x

    Homework Statement So I have to find the tangent line when x=5. I use the difference quotient, but I'm stuck at the algebra? I can't seem to figure out what steps I should take. Here's what I have: [(x+h)+1/(x+h)] - (x+1/x) I've tried numerous steps on how to solve this, but can't do...
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