1.
Given a function f(x,y) at (x0,y0). Find the two angles the directional derivative makes with the x-axis, where the directional derivative is 1. The angles lie in (-pi,pi].
2.
f(x,y) = sec(pi/14)*sqrt(x^2 + y^2)
p0 = (6,6)
3.
I use the relation D_u = grad(f) * u, where u is the...