(2tan(x)-sin(2x))/2sin(2x)=tan(x)/sin(2x)-½=tan(x),
(sin(x)/cos(x))/(2sin(x)cos(x))-½=tan(x),
1/(2cos2(x))-½=tan(x),
½(sec2(x)-1)=tan(x),
½tan2(x)=tan(x),
tan2(x)-2tan(x)=0,
tan(x)(tan(x)-2)=0,
tan(x)=0 or tan(x)=2. (sin(2x)=⅘)
x=nπ (n is an integer), x=1.1071+nπ radians.
In degrees x=180n°, 63.435°+180n°.