2. 求 ∫_0^1 (x^2 - √x) dx =？ (A)-1/3 (B)-1/6 (C)1/6(D) 1/3

3. 已知合成函數\( (f \circ g)(x) = e^{-\sqrt{x^2+1}} \) ，則下列各式之 \(f(x)\) ，\(g(x)\) ，何者不符？ (A) \(f(x) = e^{\sqrt{x}}\) ，\(g(x) = -(x^2 + 1)\) (B)\(f(x) = e^{-\sqrt{x}}\) ，\(g(x) = (x^2 + 1)\) (C)\(f(x) = \frac{x}{e}\) ，\(g(x) = e^{1-\sqrt{x^2+1}}\) (D)\(f(x) = \frac{1}{x}\) ，\(g(x) = e^{\sqrt{x^2+1}}\)