00:01
In this problem of this series, we have given this is the sigma, n is equal to this is the lower limit and this is the upper limit infinity, and 4 multiplied with minus half to the power n.
00:14
And now we have to find the third, fourth and fifth partial sum of this series.
00:19
So here for finding the third partial sum, so this would be from n is equal to 1 to 3.
00:26
So this is from n is equal to 1 to 3 and 4 minus half to the power this is n.
00:34
So first term would be here we can simply here 4 would be out of the box and then minus half to power 1 simply have minus half and then minus half to the power 2 so this would be 1 divide with 4 and then minus half to the power 3 that is minus 1 divided with 8 and now solve it.
00:57
So this would be 4 multiplied with here 8 common so this would be here minus 4 plus 2 minus 1 solve it so this would be minus 5 plus 2 that means here minus 3 so and 4 which cancelled out with 2 so this is minus 3 divide with 2 and now for the 4th partial sum we have to take from n is equal to 1 to 4 so this is 4 minus half to the power n.
01:27
And now in this here, partial sum, third parcel, sum, we have to add simply fourth term.
01:33
So this would be minus 3 divide with 2 and the fourth term would be here, like here, 4 multiplied with 6...