Opposite over adjacent
=tan^-1(1.5/3)= theta
angle theta = 26.56505118 degrees.

Try setting

, so that

. The interval then changes from

to

.
Now, the integral is

The Pythagorean identity lets you reduce the denominator:

Since

for the given interval, you have

, which means the integral is equal to
Speed: distance traveled in a given time
y=distance ( given in miles).
x = time (given in minutes)
Speed = y/x
y = 39.4x
By rearranging this y/x =39.4 ( is the constant speed). don’t forget this is mile/minutes
There are 4 x 60 minutes in 4 hours
Hence, you are asked the distance (y) in 240 min
y = 39.4x
y = 39.4 miles/minutes x (240) minutes
y = 9456 miles