Answer:
[tex]u= -\frac{1}{\sqrt{6}} ,-\frac{1}{\sqrt{6}} ,-\frac{2}{\sqrt{6}}[/tex]
Step-by-step explanation:
From the question we are told that
Temperature is given [tex]T ( x, y, z) = x + yz.[/tex]\
A fly is at (1,2,1)
Generally the direction of fly is given by
[tex]\triangleT(x,y,z) =(1,z,y)\\[/tex]
[tex]v= \triangleT(1,2,1)\\v=(1,1,2)[/tex]
Mathematically solving for the vector direction
[tex]|v|=\sqrt{1^2+1^2+2^2}[/tex]
[tex]|v|=\sqrt{6}[/tex]
[tex]u=- \frac{v}{|v|}[/tex]
[tex]u= -\frac{1}{\sqrt{6}} ,-\frac{1}{\sqrt{6}} ,-\frac{2}{\sqrt{6}}[/tex]
Therefore this the direction which should be taken to cool down soonest
