• # question_answer If ${{z}_{1}}$ and ${{z}_{2}}$ be two complex number, then  Re$({{z}_{1}}{{z}_{2}})=$ A) Re $({{z}_{1}}).\operatorname{Re}({{z}_{2}})$ B) Re $({{z}_{1}})$. Im $({{z}_{2}})$ C) Im $({{z}_{1}}).\operatorname{Re}\,({{z}_{2}})$ D) None of these

If ${{z}_{1}}$ and ${{z}_{2}}$ be two complex number then Re $({{z}_{1}}{{z}_{2}})=\operatorname{Re}({{z}_{1}})\operatorname{Re}({{z}_{2}})-\operatorname{Im}({{z}_{1}})\operatorname{Im}({{z}_{2}})$