Any ideas to find intersection between tan(t) and y1, y2, and y3 line equations?

Hello! I want to find intersection between tan(t) and the following line equations but my code instead of giving me two intersection points, just giving me one at origin(0,0)

t=0:0.01:5; 
y1=0.5*t; y2=t; y3=2*t;
i1=intersect(tan(t),y1)
i2=intersect(tan(t),y2)
i3=intersect(tan(t),y2)

HINT: There should be 2 intersection points for each one of i1, i2, and i3!

Answer 1

[Mohammed Sayan]

    ieq1=@(t) tan(t)-0.5*t; 
    ieq2=@(t) tan(t)-t; 
    ieq3=@(t) tan(t)-2*t;

    i1=fzero(ieq1,[pi 3*pi/2]);
    i2=fzero(ieq2,[pi 3*pi/2]);
    i31=fzero(ieq3,pi/4);
    i32=fzero(ieq3,[pi 3*pi/2]);

Answer 2

[Matt J]

I assume you are looking for solutions on [-pi/2, pi/2].

The only one of the functions that has an intersection anywhere there but t=0 is y2. You can find the positive solution using fzero,

   >> fun=@(t) tan(t)-2*t; [T,fval]=fzero(fun,3*pi/8)

T =

      1.1656

fval =

     4.4409e-16

The other solution is -T, due to the symmetry of the functions.

[Mohammed Sayan]

Well, that was a good try! thanks. I want all intersections greater that ZERO.

[Matt J]

You won't be able to have them all. There are infinitely many...