Recent content by batmankiller

Ah that makes a lot of sense. Quick question though, is the heat flux equivalent to the J in electric flux as well?

Yes sorry T_3 is T_2. and T_h is T_A.

So this isn't a homework problem persay, it was given information but I just couldn't wrap my head on why this was true. We have 1-d heat transfer through a planar slab. If we have a T_a for the temperature outside, then as we T_1 for the temperature on one end of the surface, and T_2 for the...

Ah ok, I don't even need the general solution, just the particular solution, so should I just consider the two particular solutions of Asin(2x)+Bcos(2x) and y=1/4 (Solving the constants A and B?)

so (cos(x)^2) is ((1+cos (2x))/2. Which is 1/2 + cos(2x)/2. Am I missing something to get it into a degree one term and a trig function? For that I get A+ B*cos(2x)+C*sin(2x)?

Homework Statement Find a particular solution yp of the differential equation 2y''+9y'+2y=(cos(x))^2Homework Equations The Attempt at a Solution I'm not really sure where to start? I solve for the homogeneous solution and get C1e^ -4.26556+C2e^-.2344355629=0. I'm just not sure where to go from...

oh ****.. yeah it's 25y.. but how does it change my particular solution? O.o

Yeah sorry, I was missing the first half of the question, if it says setup but don't solve for the coefficients for just the particular solution, is what I have correct because it keeps saying I'm wrong and I have no idea. Am I missing some steps?

Homework Statement Set up but do not solve for the appropriate particular solution yp for the differential equation y''+25y=2xsin(5x) using the Method of Undetermined Coefficients (primes indicate derivatives with respect to x). Homework Equations The Attempt at a Solution I first solved the...

Ok so apparently it accepted e^(-x/2) but not e^(-.5x). Thank you so much for your help!

umm yeah thanks so much. -.5x apparently doesn't equal -x/2 anymore. Math as we know it has changed!

Eh it's online homework and it says "answer is incorrect" -.-" I entered: e^(-.5x)(a*cos(sqrt(3)*x/2)+bsin(sqrt(3)*x/2)) and my previewed answer was in the correct format too

Nope, it's given as a homogeneous equation (set equal to 0). Unless you're saying there's something I'm missing? The full equation is y=e^(-.5x)(a*cos(*x/2)+bsin(*x/2))

Homework Statement Question: I'm confused about how to app Find the real-valued general solution of the differential equation y''+1y'+1y=0 where primes indicate differentiation with respect to x. (Use the parameters a, b, etc., for undetermined constants in your solution.) The...

Question: Find the real-valued general solution of the differential equation y''+1y'+1y=0 where primes indicate differentiation with respect to x. (Use the parameters a, b, etc., for undetermined constants in your solution.) My attempt: Use characteristic equation: r^2+r+1=0 I used the...