SOLUTION: A driver leaves his house at 7:00 a.m. and arrives at his work at 8:00 a.m. The maximum speed at which it travels is 45 miles per hour. If the speed is time dependent, describe the

Algebra ->  Functions -> SOLUTION: A driver leaves his house at 7:00 a.m. and arrives at his work at 8:00 a.m. The maximum speed at which it travels is 45 miles per hour. If the speed is time dependent, describe the      Log On


   

Question 1180129: A driver leaves his house at 7:00 a.m. and arrives at his work at 8:00 a.m. The maximum speed at which it travels is 45 miles per hour. If the speed is time dependent, describe the reasonable domain.
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
The time is strictly given as 1 hour. The distance of travel and speed are variables.

v%2Ax=d

v=d%2Fx
The MAXIMUM speed was stated, 45 mph.
d%2Fx%3C=45
but x was already given as 1 hour. This then is NOT a variable. The only outcome for the description is d%3C=45.

Answer by ikleyn(52803) About Me  (Show Source):
You can put this solution on YOUR website!
.
A driver leaves his house at 7:00 a.m. and arrives at his work at 8:00 a.m.
The maximum speed at which it travels is 45 miles per hour.
If the speed is time dependent, describe the reasonable domain.
~~~~~~~~~~~~~~~~~~~~~~~~~ 

In this problem, the meaning is hidden behind the words.


It would be naturally to ask to estimate the distance,
but then the problem would be too simple.



But if you don't bother with words, then the natural answer is:

     the distance is not more than 1*45 = 45 miles.


Here factor "1" represents the travel time of 1 hour, 
which is given in the problem as a constant value.

Solved and explained.