令x = a siny,dx = a cosy dy∫ x²/√(a² - x²) dx= ∫ (a² sin²y)(a cosy dy)/(a cosy)= a²∫ sin²y dy= (a²/2)∫ (1 - cos2y) dy= (a²/2)(y - 1/2 sin2y) + C= (a&#...