solution for implicit function with boundary condition

edit

Hello everyone I have a equation of

$$ x \sin(\theta_0)+y \cos(\theta_0)+Cy_0-a \sin(((x \cos(\theta_0)-y \sin(\theta_0))+Cx_0)/Wavelength 2 \pi) == 0$$

which is the graph of $$a \sin(x/Wavelength 2 \pi)$$

translate $Cx_0, Cy_0$ and turn $\theta$ degree

Now I want to find the value of y for every x

and the boundary condition is -5<x&lt;5 and="" -2<y&lt;2<="" p="">

I only need numerical solution So I write(for example)

xxx=1
solve([xxx*sin(theta0)+yy*cos(theta0)+Cy0-a*sin(((xxx*cos(theta0)-yy*sin(theta0))+Cx0)/Wavelength*2*pi)==0],yy)

but it only give me

yy == -1591171550/11651589*sin(-8742223/40728696*pi + 1674841/89990759*pi*yy) - 2736327944741683/32059067495364

This is not what I need How can I solve it?