Respuesta :

The path goes from x =-1 to 1, therefore t = -pi/2 to pi/2

Arc length is defined as:
[tex]\int \sqrt{(\frac{dx}{dt})^2 +(\frac{dy}{dt})^2} dt[/tex]

Answer:
[tex]\int_{-\pi/2}^{\pi/2} \sqrt{cos^2 (t) + 4sin^2(t) cos^2(t)} dt[/tex]