00:02
I've been given here 1 plus x plus x squared to power n equals this series here.
00:08
We're to find out this n equals a node a1, negative a1, a2.
00:12
So this n value, we need to find out here.
00:16
What will be that? we need to use this series here.
00:18
That is given specially here.
00:20
So we use the series here.
00:22
So what can do first? first we just replace here x with negative x.
00:27
You can see here we have here negative a1, a2, and then positive a2, a3.
00:32
In this a1 part here the coefficient of x that must be negative so that means x must be negative here so we just to place here x with negative x so we get one negative x plus x squared to the power n that will become a note negative a 1x plus a 2x square and so on we have negative 1 to the power n a 2n x to the power 2n so now it is say we have extra part 2n that will be positive so it will always come out to be positive so we can just remove this part this term will be positive.
01:15
Next we see here a1 is multiplied with a 2 so what we can do here we'll just replace here x with 1 over x in this series so let's replace your x with 1 over x and and we get a series as coming up to be.
01:42
We get 1 plus 1 over x plus 1 over x square all to the bar n...