令∫(0,2)_f(x)dx = t,注：t为定值,不是x的函数对原始两边从0到2积分：t = ∫(2x+3t)dx = ∫dx² + 3t∫dx = x²|(0,2) + 3tx|(0,2)=4 + 6t所以4 + 6t = tt = -4/5即∫(上标2下标0)f(x)dx=-4/5...