Answer:
a) 
b) 
c) the points of the form (x, -x) for x≠0
Step-by-step explanation:
a)
If φ(x, y) = arctan (y/x), the vector field F = ∇φ would be
On one hand we have,
On the other hand,
So
b)
The domain of definition of F is
i.e., all the plane X-Y except the (0,0)
c)
Here we want to find all the points such that
where k is a real number other than 0.
But this means
So, all the points in the line y = -x except (0,0) are parallel to the vector field F, that is, the points (x, -x) with x≠ 0
Answer:
2 sides of the patio are 9ft and another 2 sides are 15ft
Step-by-step explanation:
To solve this problem we have to know thata rectangle has 4 sides and 2 of them are equal to each other
This is the formula to calculate perimeter
p = perimeter 48 ft
a = side a = 9 ft
b = side b
p = 2a + 2b
we replace the known values
48ft = 2*9ft + 2b
48ft = 18ft + 2b
48ft - 18ft = 2b
30 / 2 = b
15 = b
2 sides of the patio are 9ft and another 2 sides are 15ft