numerical solution the given equation to determine the zero value of k

Hello I need to fins the numerical solution of the given equation :

I want to find the value of k where the curve cross the x-axis.

attached is the equation .also pplease see my code.

%Numerical solution to determin the value of K
density =7.9 ;%g/cm^3
Ri =0.35;%cm
Ro =0.4;%cm
Mlaser =1.5;
M =64.4+Mlaser;
l=9;%cm
Mt= density*pi*((Ro)^2-(Ri)^2)*l;
solvk =@(k)1+cos(k*l)*cosh(k*l)+ (M/Mt)*k*l(cos(k*l)*sinh(k*l))-sin(k*l)*cosh(k*l);
k =fzero(solvk,l);

Answer 1

[Torsten]

solvk = @(k) 1+cos(k*l).*cosh(k*l) + (M/Mt).*k*l.*(cos(k*l).*sinh(k*l)-sin(k*l).*cosh(k*l));
val = fzero(solvk,0.1)

[Yannick Tabot Njami]

Thanks very much Torsten . I appreciate