y = f(x),x = g(y)y = ∫(x²~2) dt/√(1 + t²)dy/dx = d(x²)/dx · 1/√(1 + x⁴) = 2x/√(1 + x⁴)dx/dy = 1/dy/dx = 1/[2x/√(1 + x⁴)] = √(1 + x⁴)/(2x)即g'(y) = √(1 + ...