Recent content by dexza666

Two surfaces are said to be tangential at a point P if they have the same tangent plane at P . Show that the surfaces z = √(2x²+2y²-1) and z = (1/3)√(x²+y²+4) are tangential at the point (1, 2, 3). differentiate first then evaluate both at 1,2,3

don't worry i can't work out how to use this thing bit complex anyways I am pretty sure it's right i just don't know how to classify the critical points. All the critical points of the function have positive second partial derivitive in y, and zero second partial derivitive in x, and zero second...

\\f(x,y) = e^x(1-\cos y) \\ \\\frac{\partial f}{\partial x} = e^x(1-\cos y),\ \ \frac{\partial f}{\partial y} = e^x\sin y \\ \\ e^x(1-\cos y) = 0 \\ \cos y = 1 \\ y = 2k\pi,\ k\in\mathbb{Z} \\ \\ e^x\sin y = 0 \\ \sin y = 0 \\ y = k\pi,\ k\in\mathbb{Z} \\ \\\mbox{critical points...

tough one find all critical points of f(x, y)=e^x(1-cos y) and classify these critical points.