The temperature in an auditorium is given by T = x2 + y2 – 2z2. A mosquito located at (2, 2, 1) in the auditorium desires to fly in such a direction that it will get warm as soon as possible. The direction, in which it must fly is
1
8i + 8j – 4k
2
2i + 2j – k
3
4i + 4j – 4k
4
–(2i + 2j - k)