1. ya que en todos hay x ^ 2 - y ^ 2 empecemos por esa llevándola en términos de t<img src="https://tex.z-dn.net/?f=x%5E2-y%5E2%3D%2812%5Ccos%20t%29%5E2-%2812%5Csin%20t%29%5E2%3D144%28%5Ccos%5E2%20t-%5Csin%5E2%20t%29%3D144%5Ccos%282t%29" />2.
Luego hallemos las diferenciales dx, dy , ds<img src="https://tex.z-dn.net/?f=dx%20%3D%20%5Cdfrac%7Bdx%7D%7Bdt%7D%5Ccdot%20dt%3D-12%5Csin%20t~dt%5C%5C%20%5C%5C%20%5C%5Cdy%3D%5Cdfrac%7Bdx%7D%7Bdt%7D%5Ccdot%20dt%3D12%5Ccos%20t~dt%5C%5C%20%5C%5C%20%5C%5Cds%20%3D%20%5Csqrt%7B%5Cleft%28%5Cdfrac%7Bdx%7D%7Bdt%7D%5Cright%29%5E2%2B%5Cleft%28%5Cdfrac%7Bdy%7D%7Bdt%7D%5Cright%29%5E2%7D~dt%3D%2012dt" />3.
Finalmente las integrales<img src="https://tex.z-dn.net/?f=%5Cdisplaystyle%5C%5C%5Coint_Cx%5E2-y%5E2~dx%3D%5Cint_%7B0%7D%5E%7B2%5Cpi%7D144%5Ccos%282t%29%5Ccdot%20%28-12%5Csin%20t%29dt%3D0%5C%5C%20%5C%5C%5Coint_Cx%5E2-y%5E2~dy%3D%5Cint_%7B0%7D%5E%7B2%5Cpi%7D144%5Ccos%282t%29%5Ccdot%20%2812%5Ccos%20t%29dt%3D0%5C%5C%20%5C%5C%5C%5C%5Coint_Cx%5E2-y%5E2~ds%3D%5Cint_%7B0%7D%5E%7B2%5Cpi%7D144%5Ccos%282t%29%5Ccdot%2012%20dt%3D0" />.