JAMB - Mathematics (1995 - No. 21)
Find the sum to infinity of the following sequence \(1, \frac{9}{10}, (\frac{9}{10})^{2}, (\frac{9}{10})^{3}\)
\(\frac{1}{10}\)
\(\frac{9}{10}\)
\(\frac{10}{9}\)
10
توضیح
\(S_{\infty} = \frac{a}{1 - r}\) (Sum to infinity of a G.P)
\(a = 1; r = \frac{9}{10}\)
\(S_{\infty} = \frac{1}{1 - \frac{9}{10}}\)
= \(\frac{1}{\frac{1}{10}} = 10\)