化简 计算或化简:(1) (-2009 ) 0 +( 1 2 ) -1 +(-2 ) 3 ;(2)8x 2 -2(x+2)(x-2)
计算或化简:(1) (-2009 ) 0 +( 1 2 ) -1 +(-2 ) 3 ;(2)8x 2 -2(x+2)(x-2)
计算或化简:(1) (-2009 ) 0 +( 1 2 ) -1 +(-2 ) 3 ;(2)8x 2 -2(x+2)(x-2)
(1)1+2-8=-5;(2)原式=8x 2 -2(x 2 -4)-8
=6x 2 .
数列1,1+2,1+2+2^2,...1+2+2^2+...+2^n的99项之和为?
第n项为1+2+2^2+...+2^(n-1)=2^n-1
99项之和=(2^1-1)+(2^2-1)+...+(2^99-1)
=(2^1+2^2+...+2^99)-n
=2^100-2-n
化简(1+1/2^2)(1+1/2^4 )(1+2/2^8)(1+2/2^16)
解:
(1+1/2^2)(1+1/2^4 )(1+1/2^8)(1+1/2^16)
=(1-1/2^2)(1+1/2^2)(1+1/2^4 )(1+1/2^8)(1+1/2^16)/(1-1/2^2) ...注:即上下同乘(1-1/2^2)
=(1-1/2^4)(1+1/2^4 )(1+1/2^8)(1+1/2^16)/(1-1/2^2) ...注:平方差公式
=(1-1/2^8)(1+1/2^8)(1+1/2^16)/(1-1/2^2)
=(1-1/2^16)(1+1/2^16)/(1-1/2^2)
=(1-1/2^32)/(1-1/2^2)
=(1-1/2^32)/(3/4)
=(4-1/2^30)/3

已知a2-b2=ab求(1) a/b-b/a (2) a2/b2+b2/a2
(1) a/b-b/a=(a^2-b^2)/ab=ab/ab=1
(2) a2/b2+b2/a2 =[(a^2-b^2)^2+2a^2*b^2/a^2*b^2=3a^2*b^2/a^2*b^2=3
(1)计算:(-2)2+4×2-1-|-8|; (2)化简:2aa2?b2-1a+b
(1)原式=4+2-8=-2;
(2)原式=
2a?(a?b) (a+b)(a?b)=
1 a?b.
1/2+3/2^2+5/2^3+7/2^4+…+2n-1/2^n
设s=1/2+3/2^2+5/2^3+7/2^4+…+2n-1/2^n
1/2s= 1/2^2+3/2^3+5/2^4+…+2n-3/2^n+2n-1/2^(n+1)
s-1/2s=1/2+2/2^2+2/2^3+2/2^4+…+2/2^n—2n-1/2^(n+1)
1/2s= 1/2+(1/2+1/2^2+1/2^3+…+1/2^n-1)—2n-1/2^(n+1)
=1/2+(1-1/2^n-1)—2n-1/2^(n+1)
s=2(1/2s)=3+7-2n/2^n
1+2+2^2+2^3+2^4......+2^63为什么等于2^64-1???
这个用到了等比数列前n项和的公式
若数列an=a1*q^n-1
则Sn=a1*((1-q^n)/(1-q))
或者这么做
令t=1+2+2^2+2^3+2^4......+2^63
则2t=2+2^2+2^3+2^4......+2^63+2^64
2t-t=t=2^64-1
希望你能满意,谢谢
(1)计算:(?2)2×5+|π?1|?9.(2)化简:4a2?4+2a+2?1a?2
(1)原式=4×5+(π-1)-3
=20+π-1-3
=16+π;
(2)原式=
4 (a+2)(a?2)+
2(a?2) (a+2)(a?2)-
a+2 (a+2)(a?2)=
4+2a?4?(a+2) (a+2)(a?2)=
a?2 (a+2)(a?2)=
1 a+2.
计算(2+1)*(2^2+1)*(2^4+1)*(2^8+1)*(2^16+1)*(2^32+1)+1
(2+1)*(2^2+1)*(2^4+1)*(2^8+1)*(2^16+1)*(2^32+1)+1
=(2^2-1)*(2^2+1)*(2^4+1)*(2^8+1)*(2^16+1)*(2^32+1)+1
=(2^4-1)*(2^4+1)*(2^8+1)*(2^16+1)*(2^32+1)+1
=(2^8-1)*(2^8+1)*(2^16+1)*(2^32+1)+1
=(2^16-1)*(2^16+1)*(2^32+1)+1
=(2^32-1)*(2^32+1)+1
=2^64-1+1
=2^64