Let $S_{n}$ represent the given statement, and use mathematical induction to prove that $S_{n}$ is true for every positive integer $n .$ See Example $1 .$ Follow these steps.
(a) Verify $S_{1}.$
(b) Write $S_{k}.$
(c) Write $S_{k+1}.$
(d) Assume that $S_{k}$ is true and use algebra to change $S_{k}$ to $S_{k+1}.$
(e) Write a conclusion based on Steps ( $a$ ) - ( $d$ ).
$$\frac{1}{2}+\frac{1}{2^{2}}+\frac{1}{2^{3}}+\dots+\frac{1}{2^{n}}=1-\frac{1}{2^{n}}$$