Recent content by jaderberg

I am trying to work out the most efficient way of updating the mean and standard deviation of a 1 dimensional set of data. The data points change frequently and by a small amount each time, but I do not want to do a complete recalculation of the mean and sd after each change, as this is...

cheers man, was beginning to wonder whether that was the case :p

oh yeah that's a typo

Homework Statement The question is shown in the attached picture. I know how to do the first part fine,and i know how to do the second part but i keep getting the wrong answer (answers are on the back of the sheet)Homework Equations tau/r=T/J (tau = shear stress, r = radial distance from...

yeah that's what i started doing, then the next equation at node v4 will be: v1 + v2 - v4*(2RCs + 2) = 0 which does not include any v3 terms so i cannot relate the two equations to eliminate v3. i cannot see any other nodes to analyse at this point so this is where i am stuck!

I have to find the frequency response equation for this circuit in the attatched photo, but i don't know how to go about analysing it as I cannot see how to do voltage loop and node analysis does not work as the two nodes are not related so nothing can be eliminated from the generated...

I have to find the frequency response equation for this circuit in the attatched photo, but i don't know how to go about analysing it as I cannot see how to do voltage loop and node analysis does not work as the two nodes are not related so nothing can be eliminated from the generated...

Yes to normalise the eigenvector the modulus has to equal 1. So it would be 1/sqrt(1^2 + 3^2) and 3/sqrt(10)

I have just started programming (started on C but currently using Ruby). This is literally my first proper program and I wanted some help and opinions. The problem is I am completely self taught using various random tutorials to learn the language and my own logic for the actual programs, so...

Homework Statement Intrinsic eqn of a curve is s = 12(sin \varphi)^{2} where s is length of arc from origin and \varphi is angle of tangent at a point with x axis. Show the cartesian eqn is (8-x)^{\frac{2}{3}}+y^{\frac{2}{3}}=4Homework Equations^{} \frac{dy}{dx}=tan\varphi...

yeh cheers i think i got that...pretty simple actually once you know what to look for

ok sorry i think i got it...correct me if I am wrong: i could write \frac{d(\frac{dy}{dt})}{dx}=\frac{dt}{dx}\frac{d(\frac{dy}{dt})}{dt}=x\stackrel{-1}{}\frac{d^2y}{dt^2} thanks guys!

im sorry but i still don't understand how to do it... rockfreak: what happens now when i change y in your expression to \frac{dy}{dt}? jam: if that was true then i would get \frac{d^2y}{dx^2}=-x\stackrel{-2}{}\frac{dy}{dt}+x\stackrel{-1}{}\frac{d^2y}{dt^2} which would produce the wrong answer...

wow that's nice..startin my engineering course at oxford next year and can get a little peak at some topics

Homework Statement If x=e^t, find \frac{dy}{dx} in terms of \frac{dy}{dt} and hence prove \frac{d^2y}{dx^2}=e\stackrel{-2t}{}(\frac{d^2y}{dt^2}-\frac{dy}{dt})Homework EquationsThe Attempt at a Solution Well i have done the first bit: x=e^t \frac{dx}{dt}=x...