8 The diagram shows the sketch of part of a curve, the pole \(O\) and the initial line.
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The polar equation of the curve is \(r = 1 + \tan \theta\).
The point \(A\) is the point on the curve at which \(\theta = \frac { \pi } { 3 }\).
The perpendicular, \(A N\), from \(A\) to the initial line intersects the curve at the point \(B\).
- Find the exact length of \(O A\).
- Given that, at the point \(B , \theta = \alpha\), show that \(( \cos \alpha + \sin \alpha ) ^ { 2 } = 1 + \frac { \sqrt { 3 } } { 2 }\).
- Hence, or otherwise, find \(\alpha\) in terms of \(\pi\).
- Show that the area of triangle \(O A B\) is \(\frac { 3 + 2 \sqrt { 3 } } { 6 }\).
- Find, in an exact simplified form, the area of the shaded region bounded by the curve and the line segment \(A B\).
[0pt]
[7 marks]
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