Bài 4: Hàm số mũ. Hàm số lôgarit
Lý thuyết Hàm số mũ. Hàm số Lôgarit
<p><strong>1. H&agrave;m số mũ</strong></p> <p><strong>a) H&agrave;m số mũ l&agrave; g&igrave;?</strong></p> <p>Định nghĩa: Cho số thực dương a kh&aacute;c 1. H&agrave;m số y = a<sup>x</sup> được gọi l&agrave; h&agrave;m số mũ của cơ số a.</p> <p><strong>b) Đạo h&agrave;m của h&agrave;m số mũ</strong></p> <p>C&ocirc;ng thức được thừa nhận: <math xmlns="http://www.w3.org/1998/Math/MathML"><munder><mi>lim</mi><mrow><mi>t</mi><mo>&#8594;</mo><mn>0</mn></mrow></munder><mfrac><mrow><msup><mi>e</mi><mi>t</mi></msup><mo>&#160;</mo><mo>-</mo><mo>&#160;</mo><mn>1</mn></mrow><mi>t</mi></mfrac><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>1</mn></math>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(1)</p> <p><span style="text-decoration: underline;"><strong>Định l&iacute; 1</strong>:</span> <strong><em>H&agrave;m số y = e<sup>x</sup> c&oacute; đạo h&agrave;m tại mọi x v&agrave;&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo mathvariant="bold-italic">(</mo><msup><mi mathvariant="bold-italic">e</mi><mi mathvariant="bold-italic">x</mi></msup><mo mathvariant="bold-italic">)</mo></mrow><mo mathvariant="bold-italic">'</mo><mo mathvariant="bold-italic">&#160;</mo><mo mathvariant="bold-italic">=</mo><mo mathvariant="bold-italic">&#160;</mo><msup><mi mathvariant="bold-italic">e</mi><mi mathvariant="bold">x</mi></msup></math>.</em></strong></p> <p>V&iacute; dụ: Giả sử&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mo>&#8710;</mo><mi>x</mi><mo>&#160;</mo><mi>l&#224;</mi><mo>&#160;</mo><mi>s&#7889;</mi><mo>&#160;</mo><mi>gia</mi><mo>&#160;</mo><mi>c&#7911;a</mi><mo>&#160;</mo><mi mathvariant="normal">x</mi><mo>,</mo><mo>&#160;</mo><mi>ta</mi><mo>&#160;</mo><mi>c&#243;</mi><mo>:</mo><mo>&#160;</mo><mo>&#8710;</mo><mi>y</mi><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msup><mi>e</mi><mrow><mi>x</mi><mo>+</mo><mo>&#8710;</mo><mi>x</mi></mrow></msup><mo>&#160;</mo><mo>-</mo><mo>&#160;</mo><msup><mi>e</mi><mi>x</mi></msup><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msup><mi>e</mi><mi>x</mi></msup><mfenced><mrow><msup><mi>e</mi><mrow><mo>&#8710;</mo><mi>x</mi></mrow></msup><mo>-</mo><mn>1</mn></mrow></mfenced></math></p> <p>Do vậy:&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mrow><mo>&#8710;</mo><mi>y</mi></mrow><mrow><mo>&#8710;</mo><mi>x</mi></mrow></mfrac><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msup><mi>e</mi><mi>x</mi></msup><mfrac><mrow><msup><mi>e</mi><mrow><mo>&#8710;</mo><mi>x</mi></mrow></msup><mo>-</mo><mn>1</mn></mrow><mrow><mo>&#8710;</mo><mi>x</mi></mrow></mfrac></math></p> <p>&Aacute;p dụng c&ocirc;ng thức (1), ta c&oacute;:&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><munder><mi>lim</mi><mrow><mo>&#8710;</mo><mi>x</mi><mo>&#8594;</mo><mn>0</mn></mrow></munder><mfrac><mrow><msup><mi>e</mi><mrow><mo>&#8710;</mo><mi>x</mi></mrow></msup><mo>-</mo><mn>1</mn></mrow><mrow><mo>&#8710;</mo><mi>x</mi></mrow></mfrac><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>1</mn></math></p> <p>Từ đ&oacute; suy ra:&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>y</mi><mo>'</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><munder><mi>lim</mi><mrow><mo>&#8710;</mo><mi>x</mi><mo>&#8594;</mo><mn>0</mn></mrow></munder><mfrac><mrow><mo>&#8710;</mo><mi>y</mi></mrow><mrow><mo>&#8710;</mo><mi>x</mi></mrow></mfrac><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msup><mi>e</mi><mi>x</mi></msup></math></p> <p>Lưu &yacute;: C&ocirc;ng thức đạo h&agrave;m của h&agrave;m số hợp đối với h&agrave;m số e<sup>u</sup> (u = u(x)) l&agrave; (e<sup>u</sup>)' = u'.e<sup>u</sup>.</p> <p><strong>ĐỊNH L&Iacute; 2: H&agrave;m số&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="bold-italic">y</mi><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">=</mo><mo mathvariant="bold">&#160;</mo><msup><mi mathvariant="bold-italic">a</mi><mi mathvariant="bold">x</mi></msup><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">(</mo><mi mathvariant="bold-italic">a</mi><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">&#62;</mo><mo mathvariant="bold">&#160;</mo><mn mathvariant="bold">0</mn><mo mathvariant="bold">,</mo><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">a</mi><mo mathvariant="bold">&#8800;</mo><mn mathvariant="bold">1</mn><mo mathvariant="bold">)</mo><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">c</mi><mi mathvariant="bold-italic">&#243;</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">&#273;</mi><mi mathvariant="bold-italic">&#7841;</mi><mi mathvariant="bold-italic">o</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">h</mi><mi mathvariant="bold-italic">&#224;</mi><mi mathvariant="bold-italic">m</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">t</mi><mi mathvariant="bold-italic">&#7841;</mi><mi mathvariant="bold-italic">i</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">m</mi><mi mathvariant="bold-italic">&#7885;</mi><mi mathvariant="bold-italic">i</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold">x</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">v</mi><mi mathvariant="bold-italic">&#224;</mi><mo mathvariant="bold">&#160;</mo><mstyle mathvariant="bold"><mrow><mo>(</mo><msup><mi>a</mi><mi>x</mi></msup><mo>)</mo></mrow></mstyle><mo mathvariant="bold">=</mo><mo mathvariant="bold">&#160;</mo><msup><mi mathvariant="bold-italic">a</mi><mi mathvariant="bold">x</mi></msup><mi mathvariant="bold-italic">l</mi><mi mathvariant="bold-italic">n</mi><mi mathvariant="bold-italic">a</mi></math></strong></p> <p>V&iacute; dụ: Ta c&oacute;&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>a</mi><mi mathvariant="italic">x</mi></msup><mo mathvariant="italic">&#160;</mo><mo mathvariant="italic">=</mo><mo mathvariant="italic">&#160;</mo><msup><mi>e</mi><mrow><mi mathvariant="italic">l</mi><mi mathvariant="italic">n</mi><msup><mi mathvariant="italic">a</mi><mi mathvariant="italic">x</mi></msup></mrow></msup><mo mathvariant="italic">&#160;</mo><mo mathvariant="italic">=</mo><mo mathvariant="italic">&#160;</mo><msup><mi>e</mi><mrow><mi mathvariant="italic">x</mi><mo mathvariant="italic">.</mo><mi mathvariant="italic">l</mi><mi mathvariant="italic">n</mi><mi mathvariant="italic">a</mi></mrow></msup></math></p> <p>Đặt u(x) = x.lna, theo Lưu &yacute; tr&ecirc;n, ta được:&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mfenced><msup><mi>a</mi><mi>x</mi></msup></mfenced><mo>'</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mfenced><msup><mi>e</mi><mrow><mi>x</mi><mi>ln</mi><mi>a</mi></mrow></msup></mfenced><mo>'</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msup><mi>e</mi><mrow><mi>x</mi><mi>ln</mi><mi>a</mi></mrow></msup><mfenced><mrow><mi>x</mi><mi>ln</mi><mi>a</mi></mrow></mfenced><mo>'</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msup><mi>a</mi><mi>x</mi></msup><mi>ln</mi><mi>a</mi></math></p> <p>LƯU &Yacute;: Với h&agrave;m hợp y = a<sup>u(x)</sup> ta c&oacute;: (a<sup>u</sup>)' = a<sup>u</sup>lna.u'</p> <p><strong>c) Khảo s&aacute;t h&agrave;m số mũ&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="bold-italic">y</mi><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">=</mo><mo mathvariant="bold">&#160;</mo><msup><mi mathvariant="bold-italic">a</mi><mi mathvariant="bold">x</mi></msup><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">(</mo><mi mathvariant="bold-italic">a</mi><mo mathvariant="bold">&#62;</mo><mn mathvariant="bold">0</mn><mo mathvariant="bold">,</mo><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">a</mi><mo mathvariant="bold">&#8800;</mo><mn mathvariant="bold">1</mn><mo mathvariant="bold">)</mo></math></strong></p> <table style="border-collapse: collapse; width: 80.0636%; height: 752px;" border="1"> <tbody> <tr> <td style="width: 29.9363%;">&nbsp;</td> <td style="width: 36.1996%; text-align: center;"><strong>y = a<sup>x</sup> (a &gt; 1)</strong></td> <td style="width: 33.8641%; text-align: center;"><strong>y = a<sup>x</sup> (0 &lt; a &lt; 1)</strong></td> </tr> <tr> <td style="width: 29.9363%;">1. Tập x&aacute;c định</td> <td style="width: 36.1996%; text-align: center;">R</td> <td style="width: 33.8641%; text-align: center;">R</td> </tr> <tr> <td style="width: 29.9363%;">2. Sự biến thi&ecirc;n</td> <td style="width: 36.1996%; text-align: center;"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>y</mi><mo>'</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msup><mi>a</mi><mi>x</mi></msup><mi>ln</mi><mo>&#160;</mo><mi>a</mi><mo>&#160;</mo><mo>&#62;</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mo>&#160;</mo><mo>&#8704;</mo><mi>x</mi></math></td> <td style="width: 33.8641%; text-align: center;"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>y</mi><mo>'</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msup><mi>a</mi><mi>x</mi></msup><mi>ln</mi><mo>&#160;</mo><mi>a</mi><mo>&#160;</mo><mo>&#60;</mo><mo>&#160;</mo><mn>0</mn><mo>&#160;</mo><mo>,</mo><mo>&#160;</mo><mo>&#8704;</mo><mi>x</mi></math></td> </tr> <tr> <td style="width: 29.9363%;">Giới hạn đặc biệt</td> <td style="width: 36.1996%; text-align: center;"><math xmlns="http://www.w3.org/1998/Math/MathML"><munder><mrow><mi>li</mi><mi>m</mi></mrow><mrow><mi>x</mi><mo>&#8594;</mo><mo>-</mo><mo>&#8734;</mo></mrow></munder><msup><mi>a</mi><mi>x</mi></msup><mo>=</mo><mn>0</mn><mo>,</mo><mo>&#160;</mo><munder><mi>lim</mi><mrow><mi>x</mi><mo>&#8594;</mo><mo>+</mo><mo>&#8734;</mo></mrow></munder><msup><mi>a</mi><mi>x</mi></msup><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mo>+</mo><mo>&#8734;</mo></math></td> <td style="width: 33.8641%; text-align: center;"><math xmlns="http://www.w3.org/1998/Math/MathML"><munder><mrow><mi>li</mi><mi>m</mi></mrow><mrow><mi>x</mi><mo>&#8594;</mo><mo>-</mo><mo>&#8734;</mo></mrow></munder><msup><mi>a</mi><mi>x</mi></msup><mo>=</mo><mo>+</mo><mo>&#8734;</mo><mo>,</mo><mo>&#160;</mo><munder><mi>lim</mi><mrow><mi>x</mi><mo>&#8594;</mo><mo>+</mo><mo>&#8734;</mo></mrow></munder><msup><mi>a</mi><mi>x</mi></msup><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>0</mn></math></td> </tr> <tr> <td style="width: 29.9363%;">Tiệm cận</td> <td style="width: 36.1996%; text-align: center;">Trục Ox l&agrave; tiệm cận ngang</td> <td style="width: 33.8641%; text-align: center;">Trục Ox l&agrave; tiệm cận ngang</td> </tr> <tr> <td style="width: 29.9363%;">3. Bảng biến thi&ecirc;n</td> <td style="width: 36.1996%; text-align: center;"><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/23112022/band-bien-thien-trand-73-sdk-diai-tich-12-tap-1-1-1lROfp.jpg" /></td> <td style="width: 33.8641%; text-align: center;"><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/23112022/band-bien-thien-trand-73-sdk-diai-tich-12-tap-1-2-dOLbF7.jpg" /></td> </tr> <tr> <td style="width: 29.9363%;">4. Đồ thị</td> <td style="width: 36.1996%; text-align: center;"><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/23112022/hinh-31-trand-73-sdk-diai-tich-12-tap-1-ed7Wsp.jpg" /></td> <td style="width: 33.8641%; text-align: center;"><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/23112022/hinh-32-trand-73-sdk-diai-tich-12-tap-1-DWgFLB.jpg" /></td> </tr> </tbody> </table> <p>2. H&agrave;m số L&ocirc;garit</p> <p><strong>a) H&agrave;m số l&ocirc;garit l&agrave; g&igrave;?</strong></p> <p>Định nghĩa: Cho số thực dương a kh&aacute;c 1, h&agrave;m số <strong>y = log<sub>a</sub>x</strong> được gọi l&agrave; h&agrave;m số l&ocirc;garit cơ số a.</p> <p>Một số v&iacute; dụ:&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>y</mi><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msub><mi>log</mi><mn>3</mn></msub><mi>x</mi><mo>,</mo><mo>&#160;</mo><mi>y</mi><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msub><mi>log</mi><mfrac><mn>1</mn><mn>4</mn></mfrac></msub><mi>x</mi><mo>,</mo><mo>&#160;</mo><mi>y</mi><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><msub><mi>log</mi><msqrt><mn>3</mn></msqrt></msub><mi>x</mi><mo>,</mo><mo>&#160;</mo><mi>y</mi><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mi>ln</mi><mo>&#160;</mo><mi>x</mi><mo>,</mo><mo>&#160;</mo><mi>y</mi><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mi>log</mi><mo>&#160;</mo><mi>x</mi></math></p> <p><strong>b) Đạo h&agrave;m của h&agrave;m số l&ocirc;garit</strong></p> <p><strong>ĐỊNH L&Iacute; 3: H&agrave;m số&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="bold-italic">y</mi><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">=</mo><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">l</mi><mi mathvariant="bold-italic">o</mi><msub><mi mathvariant="bold-italic">g</mi><mi mathvariant="bold">a</mi></msub><mi mathvariant="bold-italic">x</mi><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">(</mo><mi mathvariant="bold-italic">a</mi><mo mathvariant="bold">&#62;</mo><mn mathvariant="bold">0</mn><mo mathvariant="bold">,</mo><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">a</mi><mo mathvariant="bold">&#8800;</mo><mn mathvariant="bold">1</mn><mo mathvariant="bold">)</mo><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">c</mi><mi mathvariant="bold-italic">&#243;</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">&#273;</mi><mi mathvariant="bold-italic">&#7841;</mi><mi mathvariant="bold-italic">o</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">h</mi><mi mathvariant="bold-italic">&#224;</mi><mi mathvariant="bold-italic">m</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">t</mi><mi mathvariant="bold-italic">&#7841;</mi><mi mathvariant="bold-italic">i</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">m</mi><mi mathvariant="bold-italic">&#7885;</mi><mi mathvariant="bold-italic">i</mi><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">x</mi><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">&#62;</mo><mo mathvariant="bold">&#160;</mo><mn mathvariant="bold">0</mn><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">v</mi><mi mathvariant="bold-italic">&#224;</mi><mo mathvariant="bold">&#160;</mo><mstyle mathvariant="bold"><mrow><mo>(</mo><mi>l</mi><mi>o</mi><msub><mi>g</mi><mi>a</mi></msub><mi>x</mi><mo>)</mo></mrow></mstyle><mo mathvariant="bold">'</mo><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">=</mo><mo mathvariant="bold">&#160;</mo><mfrac><mn mathvariant="bold">1</mn><mrow><mi mathvariant="bold">x</mi><mi mathvariant="bold">l</mi><mi mathvariant="bold">n</mi><mi mathvariant="bold">a</mi></mrow></mfrac></math></strong></p> <p><strong>Đặc biệt: <math xmlns="http://www.w3.org/1998/Math/MathML"><mfenced><mrow><mi>ln</mi><mi>x</mi></mrow></mfenced><mo>'</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mfrac><mn>1</mn><mi>x</mi></mfrac></math></strong></p> <p>Lưu &yacute;: Với h&agrave;m hợp y = log<sub>a</sub>u(x), ta c&oacute;:&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mfenced><mrow><msub><mi>log</mi><mi>a</mi></msub><mi>u</mi></mrow></mfenced><mo>'</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mfrac><mrow><mi>u</mi><mo>'</mo></mrow><mrow><mi>u</mi><mi>ln</mi><mi>a</mi></mrow></mfrac></math></p> <p><strong>c) Khảo s&aacute;t h&agrave;m số l&ocirc;garit&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="bold-italic">y</mi><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">=</mo><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">l</mi><mi mathvariant="bold-italic">o</mi><msub><mi mathvariant="bold-italic">g</mi><mi mathvariant="bold">a</mi></msub><mi mathvariant="bold-italic">x</mi><mo mathvariant="bold">&#160;</mo><mo mathvariant="bold">(</mo><mi mathvariant="bold-italic">a</mi><mo mathvariant="bold">&#62;</mo><mn mathvariant="bold">0</mn><mo mathvariant="bold">,</mo><mo mathvariant="bold">&#160;</mo><mi mathvariant="bold-italic">a</mi><mo mathvariant="bold">&#8800;</mo><mn mathvariant="bold">1</mn><mo mathvariant="bold">)</mo></math></strong></p> <table style="border-collapse: collapse; width: 79.2153%; height: 683px;" border="1"> <tbody> <tr> <td style="width: 29.9363%;">&nbsp;</td> <td style="width: 36.1996%; text-align: center;"><strong>y = log<sub>a</sub>x&nbsp;(a &gt; 1)</strong></td> <td style="width: 33.8641%; text-align: center;"><strong>y = log<sub>a</sub>x (0 &lt; a &lt; 1)</strong></td> </tr> <tr> <td style="width: 29.9363%;">1. Tập x&aacute;c định</td> <td style="width: 36.1996%; text-align: center;"><math xmlns="http://www.w3.org/1998/Math/MathML"><mfenced><mrow><mn>0</mn><mo>;</mo><mo>+</mo><mo>&#8734;</mo></mrow></mfenced></math></td> <td style="width: 33.8641%; text-align: center;"><math xmlns="http://www.w3.org/1998/Math/MathML"><mfenced><mrow><mn>0</mn><mo>;</mo><mo>+</mo><mo>&#8734;</mo></mrow></mfenced></math></td> </tr> <tr> <td style="width: 29.9363%;">2. Sự biến thi&ecirc;n</td> <td style="width: 36.1996%; text-align: center;"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>y</mi><mo>'</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mfrac><mn>1</mn><mrow><mi>x</mi><mi>ln</mi><mi>a</mi></mrow></mfrac><mo>&#160;</mo><mo>&#62;</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mo>&#160;</mo><mo>&#8704;</mo><mo>&#160;</mo><mi>x</mi><mo>&#160;</mo><mo>&#62;</mo><mo>&#160;</mo><mn>0</mn></math></td> <td style="width: 33.8641%; text-align: center;"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>y</mi><mo>'</mo><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mfrac><mn>1</mn><mrow><mi>x</mi><mi>ln</mi><mi>a</mi></mrow></mfrac><mo>&#160;</mo><mo>&#60;</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mo>&#160;</mo><mo>&#8704;</mo><mo>&#160;</mo><mi>x</mi><mo>&#160;</mo><mo>&#62;</mo><mo>&#160;</mo><mn>0</mn></math></td> </tr> <tr> <td style="width: 29.9363%;">Giới hạn đặc biệt</td> <td style="width: 36.1996%; text-align: center;"><math xmlns="http://www.w3.org/1998/Math/MathML"><munder><mrow><mi>li</mi><mi>m</mi></mrow><mrow><mi>x</mi><mo>&#8594;</mo><msup><mn>0</mn><mo>+</mo></msup></mrow></munder><msub><mi>log</mi><mi>a</mi></msub><mi>x</mi><mo>=</mo><mo>-</mo><mo>&#8734;</mo><mo>,</mo><mo>&#160;</mo><munder><mi>lim</mi><mrow><mi>x</mi><mo>&#8594;</mo><mo>+</mo><mo>&#8734;</mo></mrow></munder><msub><mi>log</mi><mi>a</mi></msub><mi>x</mi><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mo>+</mo><mo>&#8734;</mo></math></td> <td style="width: 33.8641%; text-align: center;"><math xmlns="http://www.w3.org/1998/Math/MathML"><munder><mrow><mi>li</mi><mi>m</mi></mrow><mrow><mi>x</mi><mo>&#8594;</mo><msup><mn>0</mn><mo>+</mo></msup></mrow></munder><msub><mi>log</mi><mi>a</mi></msub><mi>x</mi><mo>=</mo><mo>+</mo><mo>&#8734;</mo><mo>,</mo><mo>&#160;</mo><munder><mi>lim</mi><mrow><mi>x</mi><mo>&#8594;</mo><mo>+</mo><mo>&#8734;</mo></mrow></munder><msub><mi>log</mi><mi>a</mi></msub><mi>x</mi><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mo>-</mo><mo>&#8734;</mo></math></td> </tr> <tr> <td style="width: 29.9363%;">Tiệm cận</td> <td style="width: 36.1996%; text-align: center;">Trục Oy l&agrave; tiệm cận đứng</td> <td style="width: 33.8641%; text-align: center;">Trục Oy l&agrave; tiệm cận đứng</td> </tr> <tr> <td style="width: 29.9363%;">3. Bảng biến thi&ecirc;n</td> <td style="width: 36.1996%; text-align: center;"><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/23112022/band-bien-thien-trand-75-sdk-diai-tich-12-tap-1-1-rIJUzS.jpg" /></td> <td style="width: 33.8641%; text-align: center;"><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/23112022/band-bien-thien-trand-75-sdk-diai-tich-12-tap-1-2-XtnkSP.jpg" /></td> </tr> <tr> <td style="width: 29.9363%;">4. Đồ thị</td> <td style="width: 36.1996%; text-align: center;"><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/23112022/hinh-33-trand-76-sdk-diai-tich-12-tap-1-FMXoPJ.jpg" /></td> <td style="width: 33.8641%; text-align: center;"><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/23112022/hinh-34-trand-76-sdk-diai-tich-12-tap-1-XHLroI.jpg" /></td> </tr> </tbody> </table>
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