00:06
Now here in this question, we look at ryan, right? how is driving to san francisco? now, suppose that distance to its destination is a new function of his total driving time as showing this diagram.
00:16
Now, ryan has 47 miles to its destination of 36 minutes of driving, and 30 .8 miles to its destination of 54 minutes of driving.
00:26
How many miles we have to destination after 62 minutes of driving.
00:32
Now, that means, suppose the distance are called to a wireless.
00:36
And the time i call it t, right? they obviously why should be given by a b plus a t.
00:41
Or because this is a decreasing function, i'd like to use the minus just for convenience, right? and you can find n and b, of course, from the giving conditions, right? for example, it says you have y equals 47, right? and at the t equals 36, right? so a 10 times 36.
01:01
And also it tells you that when t equals 54, and minus a times 54, right? and you are going to have, and ryan is going to have only 30 .8 miles, right? now, from this, you can easily work out the a, right? so you just take the difference between these two equations.
01:18
You find a, of course, it's going to be given by 47 minus 30 .8 divided by 54 minus 36, right? that will be, of course, given by 18, right? so if you do the calculation, you'll find this to be given by...