| Exam Board | SPS |
|---|
| Module | SPS SM Mechanics (SPS SM Mechanics) |
|---|
| Year | 2022 |
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| Session | February |
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| Topic | Geometric Sequences and Series |
|---|
8.
Show that
$$\sum _ { n = 2 } ^ { \infty } \left( \frac { 3 } { 4 } \right) ^ { n } \cos ( 180 n ) ^ { \circ } = \frac { 9 } { 28 }$$
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