u=arcsin2x
du=(2x)`dx/sqrt(1-(2x)^2)
du=2/sqrt(1-4x^2)
dv=dx
v= ∫ dx=x
∫arcsin 2xdx=x*arcsin2x- ∫ x*( 2dx)/sqrt(1-4x^2)=
=x*arcsin2x- ∫ 2xdx/sqrt(1-4x^2)=
=x*arcsin2x+ (1/4) ∫ ( -8x)dx/sqrt(1-4x^2)=
=x*arcsin2x+(1/4) ∫(1-4x^2)^(-1/2)d(1-4x^2)=
=x*arcsin2x+(1/4) *(1-4x^2)^(1/2)/(1/2) + C
= [b]x*arcsin2x +(1/2)sqrt(1-4x^2) +C[/b]