asin(1 + 2*x)
2 ------------------- ________________ / 2 \/ 1 - (1 + 2*x)
4*(1 + 2*x) ------------------- 3/2 / 2\ \1 - (1 + 2*x) /
/ 2 \ | 3*(1 + 2*x) | 8*|1 + --------------| | 2| \ 1 - (1 + 2*x) / ---------------------- 3/2 / 2\ \1 - (1 + 2*x) /