=f'(x)h(x)p(x)+ f(x)h'(x)p(x) + f(x)h(x)p'(x)将p(x)换成a(x)b(x)，就可以得到四个相乘的函数的求导公式是：(f(x)h(x)a(x)b(x))'=f'(x)h(x)a(x)b(x)+ f(x)h'(x)a(x)b(x) + f(x)h(x)a(x)b'(x)+f(x)h(x)a'(x)b(x)由此可以推导...