Yes, points in the direction of fastest increase of T so that points in the direction fastest decrease. The mosquito should fly in the direction of . The rate of change of T in the direction of vector v is the dot product of and aunitvector in the direction of v. What is a unit vector in the direcction of (4, 4, -2)?

Yes, points in the direction of fastest increase of a(x, y). Find and evaluate it at [itex](\sqrt{2}, 7)[/tex].

points perpendicular to the surface. Evaluating at (1, 1, 2) gives the normal vector at that point.

Now, you should know that a line in the direction of vector (A, B, C) though is given by the parametric equations , , and the tangent plane is given by .