JAMB - Mathematics (2009 - No. 17)
Find to infinity, the sum of the sequence \(1, \frac{9}{10}, \left(\frac{9}{10}\right)^2, \left(\frac{9}{10}\right)^3,.....\)
10
9
10/9
9/10
Објашњење
\(a=1, r=\frac{9}{10}\\
S_n = \frac{a}{1-r}\\
S_n = \frac{1}{1-\frac{9}{10}}\\
=1\div \frac{1}{10}\\
=1\times \frac{10}{1}\\
10\)
S_n = \frac{a}{1-r}\\
S_n = \frac{1}{1-\frac{9}{10}}\\
=1\div \frac{1}{10}\\
=1\times \frac{10}{1}\\
10\)