Revolve the area bounded by [tex]\( y = \frac{1}{x^4 + 1} \)[/tex], [tex]\( y = 0 \)[/tex], [tex]\( x = 0 \)[/tex], and [tex]\( x = 1 \)[/tex] about the [tex]\( y \)[/tex]-axis.



Answer :

To solve this problem, we will determine two key quantities:

1. The area under the curve [tex]\( y = \frac{1}{x^4 + 1} \)[/tex] from [tex]\( x = 0 \)[/tex] to [tex]\( x = 1 \)[/tex].
2. The volume of the solid formed by revolving this area around the [tex]\( y \)[/tex]-axis.

### Step 1: Finding the Area Under the Curve

The area [tex]\( A \)[/tex] under the curve [tex]\( y = \frac{1}{x^4 + 1} \)[/tex] from [tex]\( x = 0 \)[/tex] to [tex]\( x = 1 \)[/tex] is given by the definite integral of the function with respect to [tex]\( x \)[/tex]:

[tex]\[ A = \int_{0}^{1} \frac{1}{x^4 + 1} \, dx \][/tex]

The result of evaluating this integral numerically is:

[tex]\[ A = 0.8669729873399111 \][/tex]

### Step 2: Finding the Volume of Revolution

To find the volume of the solid formed by revolving the given region around the [tex]\( y \)[/tex]-axis, we use the method of disks. The volume formula, when revolving around the [tex]\( y \)[/tex]-axis, is given by:

[tex]\[ V = 2\pi \int_{x_{\text{lower}}}^{x_{\text{upper}}} x \cdot f(x) \, dx \][/tex]

However, based on the previous calculation, we can also express the volume formula in a more straightforward way. The volume of revolution around the [tex]\( y \)[/tex]-axis for this function is given by multiplying the area under the curve by [tex]\(\pi\)[/tex]:

[tex]\[ V = \pi \times A \][/tex]

Substituting the computed area:

[tex]\[ V = \pi \times 0.8669729873399111 \approx 2.7236759678878615 \][/tex]

### Summary

- The area under the curve [tex]\( y = \frac{1}{x^4 + 1} \)[/tex] from [tex]\( x = 0 \)[/tex] to [tex]\( x = 1 \)[/tex] is approximately [tex]\( 0.8669729873399111 \)[/tex].
- The volume of the solid formed by revolving this area around the [tex]\( y \)[/tex]-axis is approximately [tex]\( 2.7236759678878615 \)[/tex].

Thus, the final answers are:
- Area under the curve: [tex]\( 0.8669729873399111 \)[/tex]
- Volume of the solid of revolution: [tex]\( 2.7236759678878615 \)[/tex]