#include "TrueBASIC.h"
void Euler(double *y, double *x, double delta_x);

void Euler(double *y, double *x, double delta_x)
// variables slope and change introduced for sake of clarity only
{
    double change, slope;

    slope = 2*(*x);                         // slope at beginning of interval
    change = slope*delta_x;                 // estimate of change during interval
    (*y) += change;                         // new value of y
    (*x) += delta_x;                        // value of x at end of interval
}