Nguyen Duc Chi (K17 HCM) Hỏi đáp Toán 12 Toán 12 Chuyên đề Toán 12

Find an equation of the tangent line to the curve at the given point:

Theo quation of the tangent line (∆) to the curve at the given point M(x0; y0)

(∆): y = f’(x0).(x – x0) + y0; y0 = f(x0)

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4 Câu trả lời
  • Bọ Cạp
    Bọ Cạp

    d) y = \frac{{3 - 2x}}{{x - 1}} \Rightarrow y' = \frac{{ - 2\left( {x - 1} \right) - 3 + 2x}}{{{{\left( {x - 1} \right)}^2}}} = \frac{{ - 1}}{{{{\left( {x - 1} \right)}^2}}}

    y = -1

    =>\frac{{3 - 2x}}{{x - 1}} =  - 1 (x≠1)

    => 3 – 2x = -x + 1

    => x = 2

    => f’(2) = -1

    According to the topic we have

    y = f’(x0)(x – x0) + y0

    => y = -1. (x- 2) - 1

    => y = -x + 1

    Trả lời hay
    23 Trả lời 12/09/22
    • Cự Giải
      Cự Giải

      a) y = \frac{{x - 1}}{{x - 2}} \Rightarrow y' = \frac{{ - 1}}{{{{\left( {x - 2} \right)}^2}}}

      x0 = 3; y = 2

      => f’(3) = -1

      According to the topic we have

      y = f’(x0)(x – x0) + y0

      => y = -1 . (x- 3) + 2

      => y = -x + 5

      0 Trả lời 12/09/22
      • Captain
        Captain

        b) y = \frac{{2x}}{{{x^2} + 1}} \Rightarrow y' = \frac{{2\left( {{x^2} + 1} \right) - 2x.2x}}{{{{\left( {{x^2} + 1} \right)}^2}}} = \frac{{ - 2{x^2} + 2}}{{{{\left( {{x^2} + 1} \right)}^2}}}

        x0 = 0; y = 0

        => f’(0) = 2

        According to the topic we have

        y = f’(x0)(x – x0) + y0

        => y = 2 . (x- 0) + 0

        => y = 2x

        0 Trả lời 12/09/22
        • Biết Tuốt
          Biết Tuốt

          c) y = 3 – 2x + x2

          => y’ = 2x – 2

          Ta có: x0 = 1; y = 3 – 2 .1 + 12 = 2

          => f’(1) = 0

          According to the topic we have

          y = f’(x0)(x – x0) + y0

          => y = 0 . (x- 1) + 2

          => y = 2

          0 Trả lời 12/09/22