Ôn tập chương V - Đạo hàm
Hướng dẫn giải Bài 3 (Trang 176 SGK Toán Đại số & Giải tích 11)
<p>Cho h&agrave;m số&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>f</mi><mfenced><mi>x</mi></mfenced><mo>=</mo><msqrt><mn>1</mn><mo>+</mo><mi>x</mi></msqrt><mo>&#160;</mo><mo>;</mo><mo>&#160;</mo><mi>T</mi><mi>&#237;</mi><mi>n</mi><mi>h</mi><mo>&#160;</mo><mi>f</mi><mfenced><mn>3</mn></mfenced><mo>+</mo><mfenced><mrow><mi>x</mi><mo>-</mo><mn>3</mn></mrow></mfenced><mi>f</mi><mo>'</mo><mfenced><mn>3</mn></mfenced><mspace linebreak="newline"/></math></p> <p>Giải</p> <p>Ta c&oacute;&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>f</mi><mo>'</mo><mfenced><mi>x</mi></mfenced><mo>=</mo><mfrac><mn>1</mn><mrow><mn>2</mn><msqrt><mn>1</mn><mo>+</mo><mi>x</mi></msqrt></mrow></mfrac><mo>&#8658;</mo><mi>f</mi><mo>'</mo><mfenced><mn>3</mn></mfenced><mo>=</mo><mfrac><mn>1</mn><mn>4</mn></mfrac><mo>'</mo><mi>f</mi><mo>'</mo><mfenced><mn>3</mn></mfenced><mo>=</mo><mn>2</mn><mspace linebreak="newline"/><mi>V</mi><mi>&#7853;</mi><mi>y</mi><mo>&#160;</mo><mi>f</mi><mo>'</mo><mfenced><mn>3</mn></mfenced><mo>+</mo><mfenced><mrow><mi>x</mi><mo>-</mo><mn>3</mn></mrow></mfenced><mo>&#160;</mo><mo>&#160;</mo><mi>f</mi><mo>'</mo><mfenced><mn>3</mn></mfenced><mo>=</mo><mn>2</mn><mo>+</mo><mfrac><mrow><mi>x</mi><mo>-</mo><mn>3</mn></mrow><mn>4</mn></mfrac><mo>=</mo><mfrac><mrow><mi>x</mi><mo>+</mo><mn>5</mn></mrow><mn>4</mn></mfrac></math></p>
Xem lời giải bài tập khác cùng bài