Recent content by pat666

They weren't mentioned, we had to state them. THings like ductility, yield strength, youngs modulus, tensile strength etc

Homework Statement In an experiment we were given a broken piece of alluminium that was (before broken) 50mm long. Then we measured it and found the elongation. From this it is pretty easy to calculate the strain. What does this actually tell me about the material though?. Actual Question...

What is f and g? Does that mean by the product of d/dx(x^3)*? Thanks

I'm not sure what you mean? how can the answer change by using a different rule?

That is 4x^3*y but where did that come from and what do I do with it? Thanks

I need help urgently/ ODE Homework Statement Solve this ODE x^3y'+4x^2y=1/x Separation of variables won't work and I can't find an integrating factor Homework Equations The Attempt at a Solution

I still can't do this, when I try hund_mat's method I get x^4*y'+4x^3*y=1 I don't know how to solve this either?

Question. what is an exact integral?

Ok, ill try to figure it out. I can't find the y_p value for r(x) though. Do you know what it is for 1/x?

How do I do that for the non homogenous ODE?

Homework Statement x^3y'+4x^2y=1/x Homework Equations NA The Attempt at a Solution I've tried separation of variable but I can't get the ys on 1 side and the xs on the other. Please help the exam is soon and I don't know what method to use?

I'm not sure, I was hoping PF could help me out.

Homework Statement Hey, This is a question from a sample exam we are given for our engineering maths exam. Firstly given that the Fourier series contains only "sin(x)" doesn't this mean that it is an "odd" function? Can the period be calculated from the given function easily? Secondly is...

Thanks for the explanations - clears things up

http://en.wikipedia.org/wiki/RLC_circuit