(PE4) Length of a Parametric Curve#

In this lesson, we are going to see how to calculate the length of a parametric curve.

Review Videos#


Arc Length#

Length of a Parametric Curve

If a curve \(C\) is described by the parametric equations

\[ x=f(t)\qquad y=g(t) \qquad \alpha \leq t \leq \beta \]

then the length of \(C\) is:

\[ L = \int_{\alpha}^{\beta} \sqrt{\left(\dfrac{dx}{dt}\right)^2+\left(\dfrac{dy}{dt}\right)^2}\, dt \]

Example 1#

Find the length of the parametric curve:

\[ x=3\cos t\qquad \quad y=3 \sin t \qquad 0\leq t\leq 2\pi \]

Example 2#

Find the length of the parametric curve:

\[ x=3+t^4 \qquad \quad y=t^6 \qquad 0\leq t\leq 1 \]