diff ( y , x , 1 ) = tan ( x ) ; ! Digits := 32; max_terms := 30; ! x_start := 0.0; x_end := 5.0 ; diff(y,0,exact_soln_y(x_start)); glob_h := 0.00001 ; glob_look_poles := true; glob_max_iter := 10; ! exact_soln_y := proc(x) 2.0 - log(abs(cos((x)))) end;