观察下列等式,1/1*2=1-1/2;1/2*3=1/2-1/3;1/3*4=1/3-4/1;……1/1×2+1/2×3+1/3×4+1/4×5=1/1*3+1/3*5+1/5*7……+1/(2n-1)(2n+1)=17/35求n的值

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 07:20:14

观察下列等式,1/1*2=1-1/2;1/2*3=1/2-1/3;1/3*4=1/3-4/1;……1/1×2+1/2×3+1/3×4+1/4×5=1/1*3+1/3*5+1/5*7……+1/(2n-1)(2n+1)=17/35求n的值
观察下列等式,
1/1*2=1-1/2;1/2*3=1/2-1/3;1/3*4=1/3-4/1;……
1/1×2+1/2×3+1/3×4+1/4×5=
1/1*3+1/3*5+1/5*7……+1/(2n-1)(2n+1)=17/35求n的值

观察下列等式,1/1*2=1-1/2;1/2*3=1/2-1/3;1/3*4=1/3-4/1;……1/1×2+1/2×3+1/3×4+1/4×5=1/1*3+1/3*5+1/5*7……+1/(2n-1)(2n+1)=17/35求n的值
1/1×2+1/2×3+1/3×4+1/4×5=1-1/2+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)=1-1/5=4/5
1/1*3+1/3*5+1/5*7+……+1/(2n-1)(2n+1)
=1/3+1/2*(1/3-1/5)+1/2(1/5-1/7)+……+1/2*[1/(2n-1)-1/(2n+1) ]
=1/3+1/2[1/3-1/5+1/5-1/7+……+(2n-1)-1/(2n+1)]
=1/3+1/2[1/3-]
=1/2-1/(2n+1)
=17/35
解得 n=34