The generating function in partial fraction decomposition for the recurrence equation given in the previous question is ___.
(上一題的遞迴式:an=−3an−1+10an−2a_n = -3a_{n-1} + 10a_{n-2}an=−3an−1+10an−2,a0=3a_0 = 3a0=3、a1=2a_1 = 2a1=2)
參考答案與解析
G(x)=17/71−2x+4/71+5xG(x)=\dfrac{17/7}{1-2x}+\dfrac{4/7}{1+5x}G(x)=1−2x17/7+1+5x4/7。承第4題遞迴式an=−3an−1+10an−2a_n=-3a_{n-1}+10a_{n-2}an=−3an−1+10an−2(a0=3,a1=2a_0=3,a_1=2a0=3,a1=2),特徵根為2,−52,-52,−5,設G(x)(1+3x−10x2)=a0+(a1+3a0)x=3+11xG(x)(1+3x-10x^2)=a_0+(a_1+3a_0)x=3+11xG(x)(1+3x−10x2)=a0+(a1+3a0)x=3+11x,因式分解1+3x−10x2=(1+5x)(1−2x)1+3x-10x^2=(1+5x)(1-2x)1+3x−10x2=(1+5x)(1−2x),部分分式解得係數為17/717/717/7與4/74/74/7(已用數列係數逐項比對驗證吻合)。