Find an approximation of the area of the region R under the graph of the function f on the interval [0, 2]. Use n = 5 subintervals. Choose the representative points to be the midpoints of the subintervals.
f (x) = x^2 + 5

Respuesta :

Interval: [tex][0,2][/tex]

Partition: [tex]\left[0,\dfrac25\right]\cup\left[\dfrac25,\dfrac45\right]\cup\left[\dfrac45,\dfrac65\right]\cup\left[\dfrac65,\dfrac85\right]\cup\left[\dfrac85,2\right][/tex]

Midpoints: [tex]\left\{\dfrac15,\dfrac35,1,\dfrac75,\dfrac95\right\}[/tex]

Value of [tex]f(x)[/tex] at the midpoints: [tex]\left\{\dfrac{126}{25},\dfrac{134}{25},6,\dfrac{174}{25},\dfrac{206}{25}\right\}[/tex]

So the definite integral is approximated by the sum

[tex]\displaystyle\int_0^2(x^2+5)\,\mathrm dx=\frac25\left(\dfrac{126}{25}+\dfrac{134}{25}+6+\dfrac{174}{25}+\dfrac{206}{25}\right)=\dfrac{316}{25}=12.64[/tex]

Compare to the actual value of the integral,

[tex]\displaystyle\int_0^2(x^2+5)\,\mathrm dx=\dfrac{38}3\approx12.67[/tex]

The approximated area of the region is an estimate of the area covered by the region

The approximated area of the region is 12.64 square units

The given parameters are:

[tex]\mathbf{Interval = [0,2]}[/tex]

[tex]\mathbf{n = 5}[/tex] --- the sub intervals

[tex]\mathbf{f(x) = x^2 + 5}[/tex] --- the function

Start by calculating the length of each partition

[tex]\mathbf{L = \frac{2 - 0}{5} = \frac 25}[/tex]

So, the partitions are:

[tex]\mathbf{P = [0,\frac 25]\ u\ [\frac 25,\frac 45]\ u\ [\frac 45,\frac 65]\ u\ [\frac 65,\frac 85]\ u\ [\frac 85,2]}[/tex]

Calculate the midpoint of each partition

[tex]\mathbf{x = \{\frac 15, \frac 35, 1 ,\frac 75, \frac 95\}}[/tex]

Calculate f(x) at the midpoints

[tex]\mathbf{f(\frac 15) = (\frac 15)^2 + 5 = 5.04}[/tex]

[tex]\mathbf{f(\frac 35) = (\frac 35)^2 + 5 = 5.36}[/tex]

[tex]\mathbf{f(1) = 1^2 + 5 = 6}[/tex]

[tex]\mathbf{f(\frac 75) = (\frac 75)^2 + 5 = 6.96}[/tex]

[tex]\mathbf{f(\frac 95) = (\frac 95)^2 + 5 = 8.24}[/tex]

Represent the function as a definite integral as follows:

[tex]\mathbf{\int\limits^2_0 {(x^2 + 5)} \, dx = \frac 25(5.04 + 5.36 + 6 + 6.96 + 8.24)}[/tex]

[tex]\mathbf{\int\limits^2_0 {(x^2 + 5)} \, dx = \frac 25(31.6)}[/tex]

Divide

[tex]\mathbf{\int\limits^2_0 {(x^2 + 5)} \, dx = 2 \times 6.32}[/tex]

[tex]\mathbf{\int\limits^2_0 {(x^2 + 5)} \, dx = 12.64}[/tex]

Hence, the approximated area of the region is 12.64 square units

Read more about approximated areas at:

https://brainly.com/question/16654180