A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes.
We know the formula , Distance = speed * time
Speed is constant and it is 12. So it is linear
The function becomes d = 12t, x is the t is the time and d is the distance
At the starting point, t=0 and distance d=0
End point , t=45 min = 0.75 hours and distance = 12 * 0.75 = 9
So domain (t) is {}
Range (d) is {}