Answer:
L=13.715
Step-by-step explanation:
Given that
x=t + cos t
y= t - sin t
0 ≤ t ≤ 3π
[tex]\dfrac{dx}{dt}=1-sin\ t[/tex]
[tex]\dfrac{dy}{dt}=1-cos\ t[/tex]
We know that length of parametric curve given as
[tex]L=\int_{a}^{b}\sqrt{\left(\dfrac{dx}{dt}\right)^2+\left(\dfrac{dy}{dt}\right)^2}dt[/tex]
[tex]\left(\dfrac{dx}{dt}\right)^2=1+sin^2 t-2t\ sint[/tex]
[tex]\left(\dfrac{dy}{dt}\right)^2=1+cos^2 t-2t\ cost[/tex]
Now by putting the values
[tex]L=\int_{0}^{3\pi}\sqrt{3-2sin\ t-2cos\ t}\ dt[/tex]
Now by using calculator
L=13.715