用C语言编程欧拉法、梯形法、二级二阶R-K、三级三阶R-K、四级四阶R-K...答:欧拉法求解y'=-2y-4x, x0=0, y0=2, x<=1的求解如下:include<stdio.h> /*solve ode: dy/dx = -2*y -4*x*/ float fun(float x,float y){ float f;f=-2.0*y -4.0*x;return f;} int main(){ float x0=0,y0=2.0,x,y,h=0.1,t=1.0,k;/* printf("\n...