Bài tập 3 trang 143 SGK Giải tích 12

A. \(n = 4k + 1\)                 

B. \(n = 4k + 2\)

C. \(n = 4k + 3\)                 

D. \(n = 4k\)

A. \({z_1} + {z_2} \in \mathbb{R}\)             

B. \({z_1}.{z_2} \in \mathbb{R}\)

C. \({z_1} - {z_2} \in \mathbb{R}\)             

D. \(z_1^2 + z_2^2 \in \mathbb{R}\)

A. \(z \in \mathbb{R} \Leftrightarrow z = \overline z \)

B. \(z\) thuần ảo \( \Leftrightarrow z + \overline z  = 0\)

C. \(\dfrac{z}{{\overline z }} - \dfrac{{\overline z }}{z} \in \mathbb{R}\left( {z \ne 0} \right)\)

D. \({z^3} + {\left( {\overline z } \right)^3} \in \mathbb{R}\)

A. \(\dfrac{{{{\left( {1 + i} \right)}^5}}}{{{{\left( {1 - i} \right)}^3}}}\)

B. \({\left( {1 + i} \right)^5} + {\left( {1 - i} \right)^5}\)

C. \(\dfrac{{1 + i}}{{1 - i}} + \dfrac{{1 - i}}{{1 + i}}\)

D. \(\dfrac{{3 + 2i}}{{2 - i}} - \dfrac{{3 - 2i}}{{2 + i}}\)

A. \(\dfrac{{2 + i\sqrt 2 }}{{1 - i\sqrt 2 }} + \dfrac{{1 + i\sqrt 2 }}{{2 - i\sqrt 2 }}\)

B. \(\left( {2 + 3i} \right)\left( {3 - i} \right) + \left( {2 - 3i} \right)\left( {3 + i} \right)\)

C. \(\dfrac{{\left( {1 + i} \right)\left( {2 + i} \right)}}{{2 - i}} + \dfrac{{\left( {1 + i} \right)\left( {2 - i} \right)}}{{2 + i}}\)

D. \({\left( {2 + i\sqrt 3 } \right)^2} - {\left( {2 - i\sqrt 3 } \right)^2}\)