Here is the function:

function [d] = projetil(v0,a, color)
    a=a*%pi/180;
    vx=v0*cos(a);
    vy=v0*sin(a);
    dt=0.01;
    x=0;
    y=0;
    t=0;
    g=9.8;
    while y>=0
        x=vx*t;
        y=vy*t-((g*(t^2))/2);
        t=t+dt;
        plot(x, y, color);
        name=‘graf’+string(x)+’.gif’
        xs2gif(0,name);
    end
    d=x;
endfunction

And the results:

The properties:

• Blue:Initial Speed=10, Angle=15°
• Red:Initial Speed=20, Angle=15°
• Green:Initial Speed=10, Angle=30°