Final answer:
The direction of the helicopter resultant vector is 27.03 miles south of the west.
Step-by-step explanation:
To find the direction of the helicopter resultant vector, we need to add the two vectors together.
The first vector is 11 miles south, which we can represent as a vector of magnitude 11 in the negative y-direction.
The second vector is 42 miles in a direction 66 degrees east of south.
To find the components of this vector, we can use the sine and cosine functions.
The x-component is given by cos(66) * 42 = 21.16 miles.
Since it is south of the west, it is negative.
The y-component is given by sin(66) * 42 = 38.97 miles.
Since it is south, it is negative.
Adding the x-components and y-components, we get -21.16 miles west and -27.03 miles south.
Therefore, the direction of the helicopter resultant vector is 27.03 miles south of the west.