Ta có: A =1/2+1/4+1/8+1/16+....+1/256+1/512
=> 2A = 1 + 1/2 + 1/4 + 1/8 + ...+ 1/128 + 1/256
=> 2A - A = (1 + 1/2 + 1/4 + 1/8 + ...+ 1/128 + 1/256 -(1/2+1/4+1/8+1/16+....+1/256+1/512 )
A = 1 - 1/512 = 511/512
Ta có: A =1/2+1/4+1/8+1/16+....+1/256+1/512
=> 2A = 1 + 1/2 + 1/4 + 1/8 + ...+ 1/128 + 1/256
=> 2A - A = (1 + 1/2 + 1/4 + 1/8 + ...+ 1/128 + 1/256 -(1/2+1/4+1/8+1/16+....+1/256+1/512 )
A = 1 - 1/512 = 511/512
Tính nhanh tổng sau:
1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256 + 1/512 + 1/1024
A= 1/2 + 1/4 + 1/8 +1/16 +1/32 + 1/64 +1/128 + 1/256 + 1/512 + 1/1024
tìm A/tính nhanh
tính tổng dưới đây bằng cách nhanh nhất:
1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256+1/512+1/1204
tính nhanh
1/2+1/4+1/8+1/16+.......+1/256+1/512
tính nhanh tổng sau:
1/2+1/4+1/8+1/16+1/64+1/128+1/256+1/512+1/1024
các bạn giả gips mik với nha!
Tính nhanh : 1+1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256+1/512
Tính nhanh:
1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256 + 1/512
Tính nhanh tổng a,1+4+9+16+25+....+144+169. b,1+2+4+8+16+32+........+256+512+1024
1/2+1/4+1/8+1/16+......+1/256+1/512
TÝnh nhanh