Compute Δy and dy for the given values of x and dx = Δx. (Round your answers to three decimal places.)

y =

x
, x = 1, Δx = 1
Δy =
dy =

1 answer

To compute \( \Delta y \) and \( dy \), we first need to understand the function given:

\[ y = \frac{1}{x} \]

Given the values:

  • \( x = 1 \)
  • \( \Delta x = 1 \)
  • Therefore, \( x + \Delta x = 1 + 1 = 2 \)

Step 1: Calculate \( \Delta y \)

The change in \( y \) (which is \( \Delta y \)) can be computed as follows:

\[ \Delta y = y(x + \Delta x) - y(x) \]

Calculating \( y(1) \):

\[ y(1) = \frac{1}{1} = 1 \]

Calculating \( y(2) \):

\[ y(2) = \frac{1}{2} = 0.5 \]

Now we can find \( \Delta y \):

\[ \Delta y = y(2) - y(1) = 0.5 - 1 = -0.5 \]

Step 2: Calculate \( dy \)

The differential \( dy \) can be computed using the derivative of \( y \):

  1. Find the derivative \( dy/dx \):

\[ \frac{dy}{dx} = -\frac{1}{x^2} \]

Evaluating the derivative at \( x = 1 \):

\[ \frac{dy}{dx} \bigg|_{x=1} = -\frac{1}{1^2} = -1 \]

  1. Now, calculate \( dy \):

\[ dy = \frac{dy}{dx} \cdot \Delta x \]

Substituting \( \Delta x = 1 \):

\[ dy = -1 \cdot 1 = -1 \]

Final Results:

Thus, we have:

\[ \Delta y = -0.500 \qquad \text{(rounded to three decimal places)} \] \[ dy = -1.000 \qquad \text{(rounded to three decimal places)} \]

So, the answers are:

\[ \Delta y = -0.500 \] \[ dy = -1.000 \]