Answer:

Step-by-step explanation:
For this case we need a line parallel to the plane x z and yz. And by definition of parallel we see that the intersection between the xz and yz plane is the z axis. And we can take the following unitary vector to construct the parametric equations:

Or any factor of u but for simplicity let's take the unitary vector.
Then the parametric equations are given by:



Where the point given 
And then since we have everything we can replace like this:




Answer:
multiply lenght x with
Step-by-step explanation:
Answer: C
Step-by-step explanation: For a function, each x-coordinate corresponds to exactly one y-coordinate.
To determine whether the graph shown here
is a function, we can use the vertical line test.
The vertical line test tells us that if each x-coordinate on the graph corresponds to exactly one y-coordinate, then any vertical line that we draw on the graph should hit the graph at only one point.
For the graph show here, any vertical line that you draw with hit the graph at only one point which means it does pass the vertical line test.
So this graph is a <em>function</em>.