Recent content by trickycheese1

The hint wasn't from an instructor but an older student, seems it was incorrect. If we differentiate with respect to x we get d/(dx) sin(x^4/(3 y) (1+y)×1/3) = (4 x^3 (y+1) cos((x^4 (y+1))/(9 y)))/(9 y) = 0. and if we differentiate with respect to y we get d/(dy) sin(x^4/(3 y)...

Homework Statement The equations sin(xyz) = 0 and x + xy + z^3 = 0 define planes in R^3. Find the osculating plane and the curvature of the intersection of the curves at (1, 0, -1)Homework Equations Osculating plane of a curve = {f + s*f' + t*f'' : s, r are reals} Curvature = ||T'|| where T is...

Yes, I put y=0 in the equation f(ax + by) >= af(x) + bf(y), and in my calculations I tried to apply the hint but it didn't get me anywhere.

I have been struggling with this problem all day so I described it in a google search and found this forum. I have that f(d(x,y)) <= f(d(x,z)+d(z,y)) but I hit a brick wall when I try to "free" the d's out of the function, i.e. I get for example that f(d(x,z)+d(z,y)) >= (d(x,z)+d(z,y))*f(1)...