Answer:

Step-by-step explanation:
Given
Represent point A as thus;

Required
Determine the new position of A, when rotated counterclockwise
The new position will be denoted as A'
When a point is rotated counterclockwise, we start by switching the positions of x and y as follows:

Then, y is negated to give A'

Answer:
a real number
Step-by-step explanation: You didn't list the choices- a real number is all positive numbers except 0
Answer:



Step-by-step explanation:
r = Radius
h = Height
Volume of cylinder = 

Surface area is given by

Differentiating with respect to radius we get

Equating with zero we get


So, the value of the function is minimum at 

So, the radius and height which would minimize the surface area is 1.05 feet and 2.12 feet respectively.
Surface area

The minimum surface area is
.
You divide 42 miles by 12 and you get 3.5
So it would take 3 hours and 50 min