1/(2*4)+1\(4*6)+1\(6*8)+.+1\(48*50)简便计算
问题描述:
1/(2*4)+1\(4*6)+1\(6*8)+.+1\(48*50)简便计算
答
=1/2[(1/2-1/4)+(1/4-1/6)+……+(1/48-1/50)]
=1/2(1/2-1/50)
=6/25=0.24
答
1/(2*4)+1\(4*6)+1\(6*8)+.+1\(48*50)=1/2×(1/2-1/4)+1/2×(1/4-1/6)+1/2×(1/6-1/8)+.+1/2×(1/48-1/50)=1/2×(1/2-1/4+1/4-1/6+1/6-1/8+.+1/48-1/50)=1/2×(1/2-1/50)=1/2×24/50=6/25