lim(x->0) sin(2x)/tan(3x)=lim(x->) (2x)/(3x)=2/3
lim(x->0) sin(2x)/tan(3x)=lim(x->0) [sin(2x)]'/[tan(3x)]'
=lim(x->0) 2cos(2x)/[3/cos^2(3x)]=2/3
lim(x->0) sin(2x)/tan(3x)=lim(x->0) sin(2x)cos(3x)/sin(3x)
=lim(x->0) [sin(2x)cos(3x)]'/[sin(3x)]'
=lim(x->0) [2cos(2x)cos(3x)-3sin(2x)sin(3x)]/[3cos(3x)]
=2/3