letx=asinydx=acosy dy∫x^2/√(a^2-x^2) dx=a^2∫ (siny)^2 dy=(a^2/2)∫ (1-cos2y) dy=(a^2/2) [y-(1/2)sin2y] + C=(a^2/2) [arcsin(x/a)- x/√(a^2-x^2)] + C
