Error in fzero function

I have a function

function F = myfun(x,xdata)
F =x(1)*sin((2*pi/x(2))*xdata+x(3));

with lsqrcurvefit i got x=[0.3559 14.2775 0.6573]

the function has several zero crossing. I want to find the zerocrossing in the interval of [t1 t2]

I used like this

findzero=fzero(@myfun(x,xdata),[-12 -7])

or

findzero=fzero(myfun(x,xdata),-8.5)

but it says error. it does nt take the command I have to pass x into myfun but it doesnt accept.

xdata is just a time series xdata=[-25:0.01:25]

pls help

Answer 1

[Walter Roberson]

findzero=fzero(@(x) myfun(x,xdata),[-12 -7])