00:01
Hi, today we are solving the question in which population in terms of t is given as 200 plus 20t minus t square.
00:13
So if we take first we can see that from here time is given as 3 hours.
00:25
So if we put time as 3 hours so p at 3 will be given as 200 plus 20 into 3 minus 3 whole square.
00:38
So we get it equals to 251.
00:42
So population at 3 hours is 251.
00:48
Similarly, taking the next one so given as in a part this is second sub part so here time is given as 8 hours.
01:01
So if we take p as 8 similarly 200 plus 20 into 8 minus 8 whole square.
01:10
So we get it equals to 196.
01:13
Now similarly taking the third one time is given as 13 hours.
01:20
So we get it as similarly p13 will be equal to 291 and last we are given that time is equals to 18 hours.
01:32
So p18 will be equal to 236.
01:37
So from here therefore we get the required population p3 as 251, p8 as 196, p13 as 291, p18 as 236.
01:58
Now secondly we are taking in the interval from 8 to 13 moves it reaches the maximum and the decrease begins.
02:37
Now similarly taking the next one so here if we take the derivative of the given population so p dash t will be equal to 20 minus 2t...