Answer:
The resultant velocity of the helicopter is  .
.
Explanation:
Physically speaking, the resulting velocity of the helicopter ( ), measured in meters per second, is equal to the absolute velocity of the wind (
), measured in meters per second, is equal to the absolute velocity of the wind ( ), measured in meters per second, plus the velocity of the helicopter relative to wind (
), measured in meters per second, plus the velocity of the helicopter relative to wind ( ), also call velocity at still air, measured in meters per second. That is:
), also call velocity at still air, measured in meters per second. That is:
 (1)
 (1)
In addition, vectors in rectangular form are defined by the following expression:
 (2)
 (2)
Where:
 - Magnitude, measured in meters per second.
 - Magnitude, measured in meters per second.
 - Direction angle, measured in sexagesimal degrees.
 - Direction angle, measured in sexagesimal degrees. 
Then, (1) is expanded by applying (2):
 (3)
 (3)

If we know that  ,
,  ,
,  and
 and  , then the resulting velocity of the helicopter is:
, then the resulting velocity of the helicopter is:


The resultant velocity of the helicopter is  .
.