| Exam Board | SPS |
| Module | SPS FM (SPS FM) |
| Year | 2024 |
| Session | November |
| Topic | Proof by induction |
7. (a) It is conjectured that
$$\frac { 1 } { 2 ! } + \frac { 2 } { 3 ! } + \frac { 3 } { 4 ! } + \ldots + \frac { n - 1 } { n ! } = a - \frac { b } { n ! }$$
where \(a\) and \(b\) are constants, and \(n\) is an integer such that \(n \geq 2\). By considering particular cases, show that if the conjecture is correct then
$$a = b = 1$$
(b) Use induction to prove that, for \(n \geq 2\), the following is true
$$\frac { 1 } { 2 ! } + \frac { 2 } { 3 ! } + \frac { 3 } { 4 ! } + \ldots + \frac { n - 1 } { n ! } = 1 - \frac { 1 } { n ! }$$
[BLANK PAGE]