Multiple choice question: DCBADC
Fill in the blanks: 32 2 1/8 2
Answer the question:
10 、( 1)bn = 2/n(n+ 1)2)t 10 = 20/ 1 1
When 1 1, (1)d=-4 (2)n=6, there is a maximum value of 78.
12、( 1)an= 1/(2^n)(2)sn=(n- 1)×2^(n+ 1)+2)