Answer:

Step-by-step explanation:
To find the rate of change of temperature with respect to distance at the point (3, 1) in the x-direction and the y-direction we need to find the Directional Derivative of T(x,y). The definition of the directional derivative is given by:

Where i and j are the rectangular components of a unit vector. In this case, the problem don't give us additional information, so let's asume:


So, we need to find the partial derivative with respect to x and y:
In order to do the things easier let's make the next substitution:

and express T(x,y) as:

The partial derivative with respect to x is:
Using the chain rule:

Hence:

Symplying the expression and replacing the value of u:

The partial derivative with respect to y is:
Using the chain rule:

Hence:

Symplying the expression and replacing the value of u:

Therefore:

Evaluating the point (3,1)

3 is incorrect because 14.7 + 3 = 17.7
The answer of 15 - 14.7 = 0.3
0.96 or 19/20
0.96 as fraction = 96/100 = 19.2 / 20 5 into 96 is 19.2 and 5 into 100 is 20
So 0.96 is the same as 19.2/20
Since 19.2 / 20 and 19 / 20 have the same denominator, therefore the 19.2 / 20 is bigger than 19 / 20.
So the 0.96 is bigger than the 19 / 20.
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