Let u = arcsin(x) and vdv = dx/sqrt(1+x) so v = 2 sqrt(1+x)
By parts, the integral is: 2 sqrt(1+x) arcsin(x) – integral [2 sqrt((1+x)/(1 – x^2)) ]
By factoring 1 – x^2 this is seen to be
2 sqrt(1+x) arcsin(x) – integral [ 2 /sqrt(1-x) ] =
2 sqrt((1+x) arcsin(x) + 4 sqrt(1-x)
Then add the constant of integral to get 2 sqrt((1+x) arcsin(x) + 4 sqrt(1-x) + C