Question:
Find the sum of each of the following infinite series :
$10-9+8.1-\ldots \ldots \infty$
Solution:
It is Infinite Geometric Series
Here, $a=10$
$r=\frac{-9}{10}=-0.9$
$\therefore S u m=\frac{a}{1-r}=\frac{10}{1-(-0.9)}=\frac{10}{1+0.9}=\frac{10}{1.9}=\frac{100}{19}$
Sum $=\frac{100}{19}$
Click here to get exam-ready with eSaral
For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.