The <span>principle that helps us to determine the total number of outcomes in a sample space is the counting principle.
</span>The Fundamental Counting Principle: If there are “a” ways for one event
to happen, and “b” ways for a second event to happen, then there are “a
* b” ways for both events to happen.
3.12 I got the answer by dividing 25 by 8
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
Y - 2x = 8 . . . . (1)
16 + 4x = 2y . . (2)
From (1), y = 2x + 8 . . . (3)
Putting (3) into (2) gives
16 + 4x = 2(2x + 8) = 4x + 16
0 = 0
Therefore, there are infinite number of solutions.