Hướng dẫn Giải bài 4 (Trang 15, SGK Toán 10, Tập 1)
<p><strong>Câu hỏi:</strong> Cho tập hợp A, hãy xác định <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>A</mi><mo>∩</mo><mi>A</mi><mo>,</mo><mo> </mo><mi>A</mi><mo>∪</mo><mi>A</mi><mo>,</mo><mo> </mo><mi>A</mi><mo>∩</mo><mo>∅</mo><mo>,</mo><mo> </mo><mi>A</mi><mo>∪</mo><mo>∅</mo><mo>,</mo><mo> </mo><msub><mi>C</mi><mi>A</mi></msub><mi>A</mi><mo>,</mo><mo> </mo><msub><mi>C</mi><mi>A</mi></msub><mo>∅</mo></math></p>
<p><strong>Hướng dẫn giải:</strong></p>
<p><math xmlns="http://www.w3.org/1998/Math/MathML"><mo>+</mo><mo>)</mo><mo> </mo><mi>A</mi><mo> </mo><mo>∩</mo><mo> </mo><mi>A</mi><mo> </mo><mo>=</mo><mo> </mo><mi>A</mi><mspace linebreak="newline"/><mo>+</mo><mo>)</mo><mo> </mo><mi>A</mi><mo> </mo><mo>∪</mo><mo> </mo><mi>A</mi><mo> </mo><mo>=</mo><mo> </mo><mi>A</mi><mspace linebreak="newline"/><mo>+</mo><mo>)</mo><mo> </mo><mi>A</mi><mo> </mo><mo>∩</mo><mo>∅</mo><mo> </mo><mo>=</mo><mo> </mo><mo>∅</mo><mspace linebreak="newline"/><mo>+</mo><mo>)</mo><mo> </mo><mi>A</mi><mo> </mo><mo>∪</mo><mo>∅</mo><mo> </mo><mo>=</mo><mo> </mo><mi>A</mi><mspace linebreak="newline"/><mo>+</mo><mo>)</mo><mo> </mo><msub><mi>C</mi><mi>A</mi></msub><mi>A</mi><mo> </mo><mo>=</mo><mo> </mo><mi>A</mi><mo> </mo><mo>\</mo><mo> </mo><mi>A</mi><mo> </mo><mo>=</mo><mo> </mo><mo>∅</mo><mspace linebreak="newline"/><mo>+</mo><mo>)</mo><mo> </mo><msub><mi>C</mi><mi>A</mi></msub><mo>∅</mo><mo>=</mo><mi>A</mi><mo> </mo><mo>\</mo><mo> </mo><mo>∅</mo><mo> </mo><mo>=</mo><mo> </mo><mi>A</mi><mspace linebreak="newline"/></math></p>