since v is the forward velocity, v > 0
I guess the upper bound would depend on the available power for existing engines.
. The power to propel an airplane (or even a bird) forward at a velocity, v, (hence the velocity is positive) is P = Av^3 +(BL^2/ v) where A and B are positive constants specific to the particular aircraft (or bird) and L is the lift, the upward force supporting the weight of the plane (or bird). What is the implied domain of this function? Think about lower and upper bounds for velocity.
2 answers
..? How is this helpful