Explore Westonci.ca, the premier Q&A site that helps you find precise answers to your questions, no matter the topic. Our platform connects you with professionals ready to provide precise answers to all your questions in various areas of expertise. Get precise and detailed answers to your questions from a knowledgeable community of experts on our Q&A platform.

Find the arc length of the curve below on the given interval by integrating with respect to x.

y=2x^(3/2); [0, 1]


Sagot :

The arc length of [tex]y=2x^{\frac32}[/tex] over [0, 1] is given by the integral,

[tex]L=\displaystyle\int_0^1\sqrt{1+\left(\frac{\mathrm dy}{\mathrm dx}\right)^2}\,\mathrm dx[/tex]

Differentiate y with respect to x using the power rule:

[tex]\dfrac{\mathrm dy}{\mathrm dx}=\dfrac32\times2 x^{\frac32-1}=3x^{\frac12}[/tex]

Then the integral becomes

[tex]L=\displaystyle\int_0^1\sqrt{1+\left(3x^{\frac12}\right)^2}\,\mathrm dx=\int_0^1\sqrt{1+9x}\,\mathrm dx[/tex]

Substitute u = 1 + 9x and du = 9 dx :

[tex]L=\displaystyle\int_0^1\sqrt{1+9x}\,\mathrm dx=\frac19\int_1^{10}\sqrt u\,\mathrm du[/tex]

[tex]L=\displaystyle\frac19\left(\frac23u^{\frac32}\right)\bigg|_1^{10}[/tex]

[tex]L=\dfrac2{27}\left(10^{\frac32}-1^{\frac32}\right)[/tex]

[tex]L=\boxed{\dfrac2{27}\left(10^{\frac32}-1\right)}[/tex]