Answer:
[tex]\dfrac{dT}{dt}=59\ ^{\circ}C/s[/tex]
Explanation:
Given that
x = 1 + t , y = 9 + 1 3 t
Tx(2, 10) = 7 ,Ty(2, 10) = 4
T=T(x,y)
[tex]\dfrac{dT}{dt}=\dfrac{dT}{dx}\dfrac{dx}{dt}+\dfrac{dT}{dy}\dfrac{d}{dt}[/tex]
[tex]T_x=\dfrac{dT}{dx}\ ,T_y=\dfrac{dT}{dy}[/tex]
[tex]\dfrac{dx}{dt}=1[/tex]
[tex]\dfrac{dy}{dt}=13[/tex]
Tx(2, 10) = 7 ,Ty(2, 10) = 4
Now by putting the values
[tex]\dfrac{dT}{dt}=\dfrac{dT}{dx}\dfrac{dx}{dt}+\dfrac{dT}{dy}\dfrac{d}{dt}[/tex]
[tex]\dfrac{dT}{dt}=7\times 1+4\times 13\ ^{\circ}C/s[/tex]
[tex]\dfrac{dT}{dt}=59\ ^{\circ}C/s[/tex]