integrating 1/sqrt(x) from   0.00000000     to   1.00000000    
 acc=   9.99999975E-05 eps=   9.99999975E-05
 q=       1.99999106      ncalls=       12860
 exact=   2.00000000    
 estimated error=   2.99999083E-04
 actual error   =   8.98634244E-06