y = sin(sin (x))/sin( x)
y'=(cos(x)cos(sin(x))sin(x)-sin(sin(x))cos(x) )/(sin(x))^2=
(cos(x)cos(sin(x))/ sin(x))- sin(sin(x))cos(x)/ (sin(x))^2
y = sin(sin (x))/sin( x)
y'=(cos(x)cos(sin(x))sin(x)-sin(sin(x))cos(x) )/(sin(x))^2=
(cos(x)cos(sin(x))/ sin(x))- sin(sin(x))cos(x)/ (sin(x))^2