$\large\frac{1+e^{-i\theta}}{1+e^{i\theta}}$=

Question

\[\begin{array}{1 1}(1)\cos\theta+i\sin\theta&(2)\cos\theta-i\sin\theta\\(3)\sin\theta-i\cos\theta&(4)\sin\theta+i\cos\theta\end{array}\]