楼上都答非所问,问的是「推导过程」,可从定义出发.导数的商公式证明：设有函数u = f(x)及v = g(x)(u/v)' = d/dx [f(x)/g(x)] = lim(Δx→0) Δy/Δx= lim(Δx→0) [f(x + Δx)/g(x + Δx) - f(x)/g(x)]/Δx= lim(Δx...