void GLWidget2d1::paintGL(){
    glClear(GL_COLOR_BUFFER_BIT);
    glColor3ub(255,255,0);
    glBegin(GL_LINE_STRIP);
    double t=0;

    for (int i=0; i<=N; i++){
        glVertex2f(fx1(t),fy1(Points[i][1]));
        t+=tau;
    }
            glEnd();
            glColor3ub(255,255,255);
    glBegin(GL_LINES);

    glVertex2f(fx1(-200),fy1(0));
    glVertex2f(fx1(400),fy1(0));
    glVertex2f(fx1(0),fy1(-50));
    glVertex2f(fx1(0),fy1(100));
          glEnd();

}
		CA()
		{
			fx1();
		}