| Exam Board | Edexcel |
| Module | C3 (Core Mathematics 3) |
| Year | 2012 |
| Session | January |
| Topic | Addition & Double Angle Formulae |
8. (a) Starting from the formulae for \(\sin ( A + B )\) and \(\cos ( A + B )\), prove that
(b) Deduce that
$$\tan ( A + B ) = \frac { \tan A + \tan B } { 1 - \tan A \tan B }$$
(c) Hence, or otherwise, solve, for \(0 \leqslant \theta \leqslant \pi\),
$$\tan \left( \theta + \frac { \pi } { 6 } \right) = \frac { 1 + \sqrt { } 3 \tan \theta } { \sqrt { } 3 - \tan \theta }$$
(c) Hence, or otherwise, solve, for \(0 \leqslant \theta \leqslant \pi\),
(c)
$$1 + \sqrt { } 3 \tan \theta = ( \sqrt { } 3 - \tan \theta ) \tan ( \pi - \theta )$$
\section*{}