00:01
In this question we have given a function f x that is f x is equal to x squared plus a x plus b and it is told that fx has minimum value at x is equal to zero.
00:13
So first of all i am going to find the minimum value of fx.
00:16
So we know that for minimum value we have to put f dash x is equals to zero.
00:21
So i am going to differentiate this.
00:23
This is for minimum value.
00:30
So this will come out to be 2x plus a is equal to 0 from here we get x is equal to minus a by 2.
00:38
So we can say that at x is equal to minus a by 2, fx has minimum.
00:46
So i can say the solution of fx is that is given to us which is minimum fx is x is equal to minus a by 2.
01:02
But we have given that fx is minimum at x is equal to 0.
01:14
So this 2 will equals, so we can say that minus a by 2 is equal to 0 or i can say a is equal to 0.
01:21
From here we get the value of a.
01:23
So now put this value of a in fx.
01:26
So our fx is x square minus b is equal to 0...