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)

A product is the answer that you get when you multiply numbers together. So for this problem, you have 2 groups to multiply together. Since I cannot show a square or cubed x, I will put an x2 for x squared and an x3 for x cubed. You have to multiply each number in the first parentheses by each number in the second parentheses. Then combine any like sets.
(8x-3)(x2-4x+8)
8x3-32x2+64x-6x+12x-24
8x3-32x2+70x-24
So the answer is 8x cubed minus 32x squared plus 70x minus 24. Whew! That's a long one. Hope I didn't miss anything.
Answer:
That would be sina.
Step-by-step explanation:
sin(a+b) = sinacosb + cosasinb
sin(a-b) = sinacosb - cosasinb
Adding we get sin(a+b) + sin(a-b) = 2sinaccosb
so sinacosb = 1/2sin(a+b) + sin(a-b)
Answer:
5% I think
Step-by-step explanation:
Its mostly just a guess but I think its 5%