问题
填空题
已知数列{an}的通项an=33-2n,则|a1|+|a2|+…+|a10|=______.
答案
∵an=33-2n,
∴数列{an}的前6项为负数,
S10=|a1|+|a2|+…+|a10|
=a1+a2+a3+a4+a5-(a6+…+a10)
=(33-2)+(33-4)+(33-8)+(33-16)+(33-32)+(64-33)+(128-33)+(256-33)+(512-33)+
=(-2-4-8-16-32+64+128+256+512+1024)
=
+2(1-25) 1-2 64(1-25) 1-2
=1922
故答案为1922