§2正项级数 正项级数∑满足:im11=9,则 (1)9<时,∑vn收敛; (2)1或9=+∞时,∑v发散 例(1)+等+3+… 258…[2+3(n-1) 159.[1+4(n-1) ∑m(x>0§2 正项级数 (2) 1 . (1) 1 ; lim 1 或 时， 发散 时， 收敛 正项级数 满足： ，则 ∑ ∑ ∑ > = +∞ < = + →∞ n n n n n n q q u q u q u u u (2) ( 0). . (1) ; 1 1 5 9 [1 4( 1)] 2 5 8 [2 3( 1)] 1 5 9 2 5 8 1 5 2 5 1 2 ∑ > + + + + + − ⋅ ⋅ + − ⋅ ⋅ + − ⋅ ⋅ ⋅ ⋅ ⋅ ⋅ nx x n n 例 ⋯ ⋯ ⋯ n ⋯