got it now :D :D :D
\phi_{uu}=(\frac{\partial}{\partial x}(x\phi_{x}+y\phi_{y}))x_{u}+(\frac{\partial}{\partial y}(x\phi_{x}+y\phi_{y}))y_{u}
Finally worked out how to use the chain rule correctly. This is the middle step that is missing.
Sorry to dig up an old thread, but it turns out I have been set exactly the same question and after spending hours trying to get my head around it, I still can't get the answer they are looking for. I get the same answer as "arildno" which is no the answer we have been asked to show. Can anyone...
Thankyou very much for your explanation, I've pretty much got my head around it. Am I right i thinking the second line to the third all of the x change to x+y and is that a sort of rule when using summation? Thanks
Homework Statement
Ok I have the answer to a question, all the working is given, however, I'm having trouble following it.
Homework Equations
http://img695.imageshack.us/img695/426/answer.jpg The Attempt at a Solution
I am completely lost, could someone please explain the steps that have...
An event A has a 70% chance of occurring, an event B has a 40% of occurring and the event (A n B) has a 20% chance of occurring. The events are not unrelated.
If A does not occur what is the probability of B?
notation A' means (not A)
I have tried to use the formula P(B|A') = P(B n...
I was just wondering how the rest mass of an electron was first discovered, I've searched everywhere and think you guys are probably the ones that are most likely going to be able answer this question.