Recent content by cycling4life

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    Graduate Solving the Shrinking Core Model: Questions & Solutions

    I have this solution that I don't quite understand d(ro*pi*D^3/6)/d(t)=-kr*Cao*pi*D^2 from here I would have thought to separate the variables and integrate but the solution says ro/2* d(D)/d(t) = -kr Cao I guess my question is how are you able to do that? If you take the derivative...
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    Can You Define a Function for an Entire Column in Excel Using VBA?

    Is it possible to define a function for an entire column in excel? I have data importing from a chemical process simulator and every time it populates a row it will insert a blank row and I need to copy my formulas. Can I make it so, for example, column B is always equal to Column A+something...
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    Graduate Solve Navier Stokes Eq for Vo | Don't Get Prof's Answer

    I need to solve 0=u[(d/dr)((1/r)*(d/dr)(r*Vo))] for Vo the prof gets Vo=Co*r/2+C1/r I don't get the same answer as him, does anyone know how to do this?
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    Graduate Integrate dx/(1-x): Solve (2/3a)(1-(1-aW)^(3/2))

    In part of a derivation they have, Integrate dx/(1-x) = (1-aW)^(1/2) dW I get -ln(1-x) = (-2/3a)*(1-aW)^(3/2) but they say it's ln(1/(1-X)) = (2/3a)((1-(1-AW)^(3/2)) Can anyone tell me how they get that extra "1-"?
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    Undergrad Chain rule and cylindrical coordinates

    I'm trying to understand this one derivation but this one part keeps messing me up; theta = tan^-1 (y/x) r^2 = x^2 + y^2 d theta/ d x = y/ (x^2 + y^2) how did they get this line?
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    Undergrad IVP Solving with Integrating Factor: Finding a Solution

    I keep struggling to find a solution to this IVP. We are supposed to use integrating factors y'-(1/t)y=8t^2+te^t t>0, y(1)=6 I get an integrating factor of (1/t) and general solution of y=4t^3+te^t+c but then i get e+2 for c. This doesn't seem correct to me, any suggestions?