Remember that e is equals to 2.717 something and to find the value of the infinities, you must consider there signs. So the e^infinity approaches to infinity while the e^-infinity approaches to zero. I hope you are satisfied with my answer and feel free to ask for more
Just calculate second term - first term = -4 - (-15)
Answer:
The electrician has 14 feet of cable.
For a better understanding of the solution provided here please find the diagram attached.
Please note that in coordinate geometry, the coordinates of the midpoint of a line segment is always the average of the coordinates of the endpoints of that line segment.
Thus, if, for example, the end coordinates of a line segment are
and
then the coordinates of the midpoint of this line segment will be the average of the coordinates of the two endpoints and thus, it will be:

Thus for our question the endpoints are
and
and hence the midpoint will be:


Thus, Option C is the correct option.