We read your photo as:

Evaluate the limit _x infinity (x2 - x)/(x3 + 2x) using L'Hôpital's rule and differentiate y = 32.

Mathematics

ScanSolve AI Answer

Step-by-step solution

14 steps

1. Evaluate lim⁡x→∞x2−xx3+2x\lim_{x \to \infty} \frac{x^2 - x}{x^3 + 2x} using L'Hôpital's rule.

Step 1: Check the form of the limit.
As x→∞x \to \infty, the numerator x2−x→∞x^2 - x \to \infty and the denominator x3+2x→∞x^3 + 2x \to \infty.
This is an indeterminate form ∞∞\frac{\infty}{\infty}, so L'Hôpital's rule can be applied.

Step 2: Apply L'Hôpital's rule by differentiating the numerator and the denominator.

lim⁡x→∞ddx(x2−x)ddx(x3+2x)=lim⁡x→∞2x−13x2+2\lim_{x \to \infty} \frac{\frac{d}{dx}(x^2 - x)}{\frac{d}{dx}(x^3 + 2x)} = \lim_{x \to \infty} \frac{2x - 1}{3x^2 + 2}

Step 3: Check the form of the new limit.
As x→∞x \to \infty, the numerator 2x−1→∞2x - 1 \to \infty and the denominator 3x2+2→∞3x^2 + 2 \to \infty.
This is still an indeterminate form ∞∞\frac{\infty}{\infty}, so apply L'Hôpital's rule again.

Step 4: Apply L'Hôpital's rule a second time.

lim⁡x→∞ddx(2x−1)ddx(3x2+2)=lim⁡x→∞26x\lim_{x \to \infty} \frac{\frac{d}{dx}(2x - 1)}{\frac{d}{dx}(3x^2 + 2)} = \lim_{x \to \infty} \frac{2}{6x}

Step 5: Evaluate the limit.

lim⁡x→∞26x=lim⁡x→∞13x=0\lim_{x \to \infty} \frac{2}{6x} = \lim_{x \to \infty} \frac{1}{3x} = 0

The limit is 0\boxed{0}.

2. Differentiate the following functions:

Part a· 4 steps

y=(1+3x2)23y = \sqrt[3]{(1+3x^2)^2}

  1. Rewrite the function using fractional exponents.

    y=(1+3x2)2/3y = (1+3x^2)^{2/3}
  2. Apply the chain rule dydx=nun−1dudx\frac{dy}{dx} = n u^{n-1} \frac{du}{dx}, where u=1+3x2u = 1+3x^2 and n=23n = \frac{2}{3}.

    dydx=23(1+3x2)23−1⋅ddx(1+3x2)\frac{dy}{dx} = \frac{2}{3}(1+3x^2)^{\frac{2}{3}-1} \cdot \frac{d}{dx}(1+3x^2)
  3. Differentiate the inner function.

    ddx(1+3x2)=0+3(2x)=6x\frac{d}{dx}(1+3x^2) = 0 + 3(2x) = 6x
  4. Substitute and simplify.

    dydx=23(1+3x2)−1/3⋅(6x)\frac{dy}{dx} = \frac{2}{3}(1+3x^2)^{-1/3} \cdot (6x) dydx=12x3(1+3x2)−1/3\frac{dy}{dx} = \frac{12x}{3}(1+3x^2)^{-1/3} dydx=4x(1+3x2)−1/3\frac{dy}{dx} = 4x(1+3x^2)^{-1/3}

    The derivative is 4x(1+3x2)−1/3\boxed{4x(1+3x^2)^{-1/3}} or 4x1+3x23\boxed{\frac{4x}{\sqrt[3]{1+3x^2}}}.

Part b· 4 steps

y=cosec 34x2y = \text{cosec } \frac{3}{4}x^2

  1. Recall the derivative of cosec(u)\text{cosec}(u), which is −cosec(u)cot(u)dudx-\text{cosec}(u)\text{cot}(u)\frac{du}{dx}.

    Here, u=34x2u = \frac{3}{4}x^2.

  2. Differentiate uu with respect to xx.

    dudx=ddx(34x2)=34(2x)=32x\frac{du}{dx} = \frac{d}{dx}\left(\frac{3}{4}x^2\right) = \frac{3}{4}(2x) = \frac{3}{2}x
  3. Apply the chain rule.

    dydx=−cosec(34x2)cot(34x2)⋅(32x)\frac{dy}{dx} = -\text{cosec}\left(\frac{3}{4}x^2\right)\text{cot}\left(\frac{3}{4}x^2\right) \cdot \left(\frac{3}{2}x\right)
  4. Rearrange the terms.

    dydx=−32x cosec(34x2)cot(34x2)\frac{dy}{dx} = -\frac{3}{2}x \text{ cosec}\left(\frac{3}{4}x^2\right)\text{cot}\left(\frac{3}{4}x^2\right)

    The derivative is −32x cosec(34x2)cot(34x2)\boxed{-\frac{3}{2}x \text{ cosec}\left(\frac{3}{4}x^2\right)\text{cot}\left(\frac{3}{4}x^2\right)}.

Part c· 6 steps

x2y+y2+4x=1x^2y + y^2 + 4x = 1

  1. Differentiate both sides of the equation with respect to xx.

    Remember to use the product rule for x2yx^2y and the chain rule for y2y^2.

    ddx(x2y)+ddx(y2)+ddx(4x)=ddx(1)\frac{d}{dx}(x^2y) + \frac{d}{dx}(y^2) + \frac{d}{dx}(4x) = \frac{d}{dx}(1)
  2. Apply the differentiation rules.

    For ddx(x2y)\frac{d}{dx}(x^2y): Use the product rule (u′v+uv′)(u'v + uv'), where u=x2u=x^2 and v=yv=y.

    (2x)y+x2dydx(2x)y + x^2\frac{dy}{dx}

    For ddx(y2)\frac{d}{dx}(y^2): Use the chain rule.

    2ydydx2y\frac{dy}{dx}

    For ddx(4x)\frac{d}{dx}(4x):

    44

    For ddx(1)\frac{d}{dx}(1):

    00
  3. Substitute these derivatives back into the equation.

    2xy+x2dydx+2ydydx+4=02xy + x^2\frac{dy}{dx} + 2y\frac{dy}{dx} + 4 = 0
  4. Group terms containing dydx\frac{dy}{dx} on one side and other terms on the other side.

    x2dydx+2ydydx=−2xy−4x^2\frac{dy}{dx} + 2y\frac{dy}{dx} = -2xy - 4
  5. Factor out dydx\frac{dy}{dx}.

    dydx(x2+2y)=−2xy−4\frac{dy}{dx}(x^2 + 2y) = -2xy - 4
  6. Solve for dydx\frac{dy}{dx}.

    dydx=−2xy−4x2+2y\frac{dy}{dx} = \frac{-2xy - 4}{x^2 + 2y}

    This can also be written as:

    dydx=−2(xy+2)x2+2y\frac{dy}{dx} = -\frac{2(xy + 2)}{x^2 + 2y}

    The derivative is −2(xy+2)x2+2y\boxed{-\frac{2(xy + 2)}{x^2 + 2y}}.

Was this helpful?

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question