Chapter 4.5, Problem 257E

The temperature T at a point (x. y) is T(x. y) and is measured using the Celsius scale. A fly crawls so that its position after a’ seconds is given by $x=\sqrt{1+t}$ and $y=2+\frac{1}{3}t$ where x and y are measured in centimeters. The temperature function satisfies $T_x\left(2,3\right)=4$ and $T_y\left(2,3\right)=3$ . How fast is the temperature increasing on the fly’s path after 3 sec?