2025 IGCSE Additional Mathematics February/March 0606/12 Q6

It is given that \(\tan\theta=\dfrac{\sqrt5}{5}\) and \(180^\circ<\theta<360^\circ\).

1. Find the value of \(\cos\theta\).[2]
2. Find the value of \(\sin\theta\).[1]
3. Find the value of \(\sec\theta+\cot\theta\).
   Give your answer in the form \(\dfrac{a+b\sqrt c}{\sqrt5}\), where \(a\), \(b\) and \(c\) are integers.[2]