Recent content by TheAntithesis

I was thinking it couldn't be that simple, apparently it is lol, thanks

Homework Statement Let f = f(u,v) where u = x+y , v = x-y Find f_{xx} and f_{yy} in terms of f_u, f_v, f_{uu}, f_{vv}, f_{uv} Then express the wave equation \frac{\partial^2f}{\partial x^2} - \frac{\partial^2f}{\partial y^2} = 0 Homework Equations Chain rule, product rule...

Ok let me know if this makes any sense at all... After changing it to polar coordinates, we get \lim_{r \to 0} r^2 cos(\theta)sin^3(\theta) Let \epsilon > 0. We want to find \delta > 0 such that if 0<r< \delta then |r^2 cos(\theta)sin^3(\theta) - 0| < \epsilon since...

Wolfram? http://www.wolframalpha.com/input/?i=lim+%28x%2Cy%29-%3E%280%2C0%29+xy^3%2F%28x^2+%2B+y^2%29

If y = 0 then xy^3 = 0 then xy^3/(x^2+y^2) = 0/x^2 = 0 so the limit must be 0

Homework Statement Apply the definition of the limit to show that lim (x,y)-->(0,0) xy^3/(x^2+y^2) = 0 Homework Equations Definition of the limit: lim (x,y)-->(a,b) f(x,y) = L if for every number epsilon > 0 there is a corresponding number delta > 0 such that if (x,y) is in the...

Concerning the IVP dy/dx = (1 + y^(2)*sinx)/(y(2cosx - 1)) with y(0) = 1 Let f(x,y) = (1 + y^(2)*sinx)/(y(2cosx - 1)). Find a rectangular region in the plane, centred at the point (0,1) and on which the two functions f and f_y are continuous. Explain why the problem has a unique solution on...

I don't want the answer, just a little help getting there. The question asks to integrate this: Triple integral I'm thinking to convert it to cylindrical but I have no idea how to convert the bounds. I can convert the actual expression z/sqrt(x^2+y^2) into cylindrical no problem. If I had...

Oh god.. Ok say the point is (-5,10,13) with its position vector v and the line is given by equation r(t) = (-57,75,0) + t(-4,5,-1). A point on the line is P(-4,5,-1) so that's the position vector u. Then the line between the two points would be would be v - u = w = (-5,10,3) - (-4,5,-1)...

Ok cool, thanks. I'm guessing my answer will be a function of t?

Re-write the line as in the form (a+pt,b+qt,c+rt) ? I still don't know what to do with the t.

I want to find the minimum distance between a point (i,j,k) and the line given by parametric equations x(t)=a+pt , y(t)=b+qt , z(t)=c+rt. I know how to find the distance between a point and a normal line (non parametric), but I have no idea how to go about finding the distance here. How...

Homework Statement A 1000kg car pushes a 2000kg truck which has a dead battery. When the car driver pushes on the accelerator, the drive wheels of the car push back against the ground with a force of 4500N. Rolling friction can be ignored. What is the magnitude of the force of the car on the...