
function [x,y]=untitled(esempio)

clf;

% esempio=12;

switch esempio
    
    case 1
        
        x=-8:0.01:8;
        y=sin(x);
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
    case 2
        
        t=0:0.01:pi;
        x=sin(t);
        y=cos(t);
        
        hold on;
        
        axis square
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
        
    case 3
        
        x=-5:0.01:5;
        y=abs(x);
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
        
        
    case 4
        
        axis normal;
        
        x=-10:0.01:10;
        y=-x.^2;
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
        
        
    case 5
        
        axis normal;
        
        x=-10:0.01:10;
        y=x.^2;
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
        
        
    case 6
        
        axis normal;
        
        x=-100:0.01:100;
        y=x.^3;
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
        
    case 7
        
        axis normal;
        
        x=-10:0.01:10;
        y=1./(1+x.^2);
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
        
        
    case 8
        
        axis normal;
        
        x=-10:0.01:10;
        y=(x.^2+100+x.^4)./(1+x.^2);
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
        
        
    case 9
        
        axis normal;
        
        x=-10:0.01:10;
        y=(3*x.^5-1000*x.^3)./(1000+10*x.^4);
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
        
    case 10
        
        axis normal;
        
        x=-10:0.01:10;
        y=(x.^2).^(1/3);
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
        
        
    case 11
        
        axis normal;
        
        x=0:0.01:2;
        y=x.^2;
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        y=x.^1;
        plot(x,y,'k','Linewidth',2);
        plot(x,zeros(size(x)),'k');
        
        y=x.^0.5;
        plot(x,y,'g','Linewidth',2);
        plot(x,zeros(size(x)),'k');
        
        
        
        hold off;
        
    case 12
        
        axis normal;
        
        x=-3:0.01:3;
        y=2.^x;
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        y=1.^x;
        plot(x,y,'k','Linewidth',2);
        plot(x,zeros(size(x)),'k');
        
        y=0.5.^x;
        plot(x,y,'g','Linewidth',2);
        plot(x,zeros(size(x)),'k');
        
        
        hold off;
        
        
    case 13
        
        axis normal;
        
        x=eps:0.01:10;
        y=log(x);
        
        hold on;
        plot(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        
        hold off;
        
    case 14
        
        x=-6.28:0.01:6.28;
        
        yc=-1.3:0.01:1.3;
        
        y=tan(x);
        
        hold on;
        semilogy(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k')
        % plot(zeros(size(yc)),yc,'k')
        plot(2*pi*ones(size(yc)),yc,'g-.')
        plot(-2*pi*ones(size(yc)),yc,'g-.')
        hold off;
        
        
    case 15
        
        x=-10:0.01:10;
        
        
        y=tanh(x);
        
        hold on;
        semilogy(x,y,'r','Linewidth',2);
        plot(x,zeros(size(x)),'k');
        %plot(2*pi*ones(size(yc)),yc,'g-.')
        %plot(-2*pi*ones(size(yc)),yc,'g-.')
        hold off;
        
    case 16
        
        axis normal;
        
        x=-2*pi:0.01:2*pi;
        xx=-7:0.01:7;
        y=sin(x);
        
        hold on;
        plot(x,y,'k','Linewidth',2);
        %plot(x,zeros(size(x)),'k')
        
        
        y=sin(x+1);
        plot(x,y,'r','Linewidth',2);
        %plot(x,zeros(size(x)),'r');
        
        y=sin(x-1);
        plot(x,y,'g','Linewidth',2);
        plot(xx,zeros(size(xx)),'k-.');
        
        
        
        hold off;
        
        
    case 17
        
        axis normal;
        
        x=-2*pi:0.01:2*pi;
        xx=-7:0.01:7;
        y=sin(x);
        
        hold on;
        plot(x,y,'k','Linewidth',2);
        %plot(x,zeros(size(x)),'k')
        
        
        y=-sin(x);
        plot(x,y,'r','Linewidth',2);
        %plot(x,zeros(size(x)),'r');
        
        plot(xx,zeros(size(xx)),'k-.');
        
        hold off;
        
        
    case 18
        
        axis normal;
        
        x=-2*pi:0.01:2*pi;
        xx=-7:0.01:7;
        
        hold on;
        y=sin(x);
        plot(x,y,'k','Linewidth',2);
        %plot(x,zeros(size(x)),'k')
        
        
        y=2*sin(x);
        plot(x,y,'r','Linewidth',2);
        %plot(x,zeros(size(x)),'r');
        
        y=0.5*sin(x);
        plot(x,y,'g','Linewidth',2);
        
    case 19
        
        axis normal;
        
        x=-2*pi:0.01:2*pi;
        xx=-7:0.01:7;
        
        hold on;
        y=sin(x);
        plot(x,y,'k','Linewidth',2);
        %plot(x,zeros(size(x)),'k')
        
        
        y=sin(2*x);
        plot(x,y,'r','Linewidth',2);
        %plot(x,zeros(size(x)),'r');
        
        y=sin(0.5*x);
        plot(x,y,'g','Linewidth',2);
        
        plot(xx,zeros(size(xx)),'k-.');
        
        
        
        hold off;
        
        
    case 20
        
        axis equal;
        
        x=-2*pi:0.01:2*pi;
        xx=-7:0.01:7;
        
        
        
        subplot(2,1,1)
        y=sin(x);
        
        hold on;
        plot(x,y,'k-','Linewidth',2);
        %plot(x,zeros(size(x)),'k')
        plot(xx,zeros(size(xx)),'k');
        hold off;
        
        subplot(2,1,2)
        hold on;
        y=(sin(abs(x)));
        plot(x,y,'r','Linewidth',2);
        plot(x,-ones(size(x)),'k')
        plot(xx,zeros(size(xx)),'k');
        hold off;
        %plot(x,zeros(size(x)),'r');
        
        %plot(xx,zeros(size(xx)),'k');
        
        
    case 21
        
        axis equal;
        
        a=2;
        
        x=-a:0.01:a;
        
        
        y=1./x;
        hold on;
        subplot(4,1,1);
        plot(x,y,'k-','Linewidth',2);
        hold off;
        
        x=eps:0.01:a;
        y=log(x);
        hold on;
        subplot(4,1,2);
        plot(x,y,'k-','Linewidth',2);
        hold off;
        
        
        x=eps:0.01:a;
        y=1./log(x);
        hold on;
        subplot(4,1,3);
        plot(x,y,'k-','Linewidth',2);
        hold off;
        
        
        x=1-0.1:0.0001:1+0.1;
        y=1./log(x);
        hold on;
        subplot(4,1,4);
        plot(x,y,'k-','Linewidth',2);
        hold off;
        
        
    case 22
        
        clf;
        
        axis normal;
        
        a=10;
        
        x=-a:0.01:-0.01;
        
        y=1./x;
        hold on;
        plot(x,y,'k-','Linewidth',2);
        
        x=0:0.01:a;
        y=x;
        plot(x,y,'k-','Linewidth',2);
        hold off;
        
    case 23
        
        clf;
        
        axis normal;
        
        a=10;
        
        x=-a:0.01:a;
        
        y=x.^3;
        hold on;
        plot(x,y,'k-','Linewidth',2);
        hold off
        
        
    case 24
        
        clf;
        
        axis normal;
        
        a=1;
        
        x=0:0.01:a;
        
        y=x.^2;
        hold on;
        plot(x,x,'b-','Linewidth',1);
        plot(x,zeros(size(x)),'k-','Linewidth',1);
        plot(zeros(size(x)),x,'k-','Linewidth',1);
        plot(x,y,'k-','Linewidth',2);
        
        plot(y,x,'r-','Linewidth',2);
        
        hold off
        
        
    case 25
        
        clf;
        
        axis normal;
        
        a=2;
        
        x=0.05:0.01:2; xx=0:0.1:8;
        
        
        y=exp(x);
        hold on;
        plot(xx,xx,'b-','Linewidth',1);
        plot(xx,zeros(size(xx)),'k-','Linewidth',1);
        plot(zeros(size(x)),x,'k-','Linewidth',1);
        plot(x,y,'k-','Linewidth',2);
        
        plot(y,x,'r-','Linewidth',2);
        
        hold off
        
        
    case 26
        
        clf;
        
        axis normal;
        
        a=pi/2;
        
        x=-pi/2:0.01:pi/2; xx=-a:0.01:a;
        
        
        y=sin(x);
        hold on;
        plot(xx,xx,'b-','Linewidth',1);
        plot(xx,zeros(size(xx)),'k-','Linewidth',1);
        plot(zeros(size(x)),x,'k-','Linewidth',1);
        plot(x,y,'k-','Linewidth',2);
        
        plot(y,x,'r-','Linewidth',2);
        
        hold off
 
        
            case 27
        
        clf;
        
        axis normal;
        
        ax=-2; bx=5;
        ay=-2; by=5;
        
        x=pi/2:0.01:3*pi/2; xx=ax:0.01:bx; yy=ay:0.01:by;
        
        
        y=sin(x);
        hold on;
        plot(xx,xx,'b-','Linewidth',1); % BISETTRICE
        plot(xx,zeros(size(xx)),'k-','Linewidth',1); %asse x
        plot(zeros(size(yy)),yy,'k-','Linewidth',1);
        
        plot(x,y,'k-','Linewidth',2); % f
        
        plot(y,x,'r-','Linewidth',2); % inv f
        
        hold off
        
        
                    case 28
        
        clf;
        
        axis normal;
        
        ax=-1.5; bx=3.5;
        ay=-1.5; by=3,5;
        
        x=0:0.01:pi; xx=ax:0.01:bx; yy=ay:0.01:by;
        
        
        y=cos(x);
        hold on;
        plot(xx,xx,'b-','Linewidth',1); % BISETTRICE
        plot(xx,zeros(size(xx)),'k-','Linewidth',1); %asse x
        plot(zeros(size(yy)),yy,'k-','Linewidth',1);
        
        plot(x,y,'k-','Linewidth',2); % f
        
        plot(y,x,'r-','Linewidth',2); % inv f
        
        hold off
        
end