c.

ln|x-\\\\sqrt(x^(2)+1)|+C

d.

ln|x^(2)-\\\\sqrt(x^(2))+1|+C

\ 18. If

\\\\int_0^(\\\\infty ) e^(-x^(2))dx=(\\\\sqrt(\\\\pi ))/(2)

, then

\\\\int_0^(\\\\infty ) (e^(-x))/(\\\\sqrt(x))dx

is\ a.

(\\\\sqrt(\\\\pi ))/(2)

\ b.

\\\\sqrt(\\\\pi )

\ c.

\\\\pi

\ d.

(\\\\pi )/(2)

c. lnxx2+1+C d. lnx2x2+1+c 18. If 0ex2dx=2, then 0xexdx is a. 2 b. c. d. 2