【摘要】 本文讨论了n年延付年金的现时值a n|i=k为已知时求利率i的数值解法。通过数学分析 ,得到几个新的迭代公式 :①is+1=is- ( 1+is) kis- 1+( 1+is) -nk(n +1)is- (n -k) ;②is+1=is- 1+isn -k[kis- 1+( 1+is) -n];③is+1=is( 1- k -a n|isn -k ) ,其中初值i0 =2 (n -k)k(n +1) 。更多还原

【Abstract】 In this paper,a numerical solution of the annuity rate equation a ｜i =k is given when the n-year annuity-immediate a ｜i =k is know.By mathematical analysis,some new iteration formulae are obtained as follows :(1) i s+1 =i s-(1+i s)ki s-1+(1+i s) -n k(n+1)i s-(n-k);(2)i s+1 =i s-1+i sn-k[ki s-1+(1+i s) -n ];(3)i s+1 =i s(1-k-a ｜is n-k) while i 0=2(n-k)k(n+1) .更多还原