题目内容
观察下面计算:
情形1:2×
=4,2+
=4; 情形2:3×
=
,3+
=
;情形3:4×
=
,4+
=
;…
(1)根据上述规律,写出情形n;
(2)根据共同特征,写出你的猜想,并证明你的猜想的正确性.
情形1:2×
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 2 |
| 9 |
| 2 |
| 3 |
| 2 |
| 9 |
| 2 |
| 4 |
| 3 |
| 16 |
| 3 |
| 4 |
| 3 |
| 16 |
| 3 |
(1)根据上述规律,写出情形n;
(2)根据共同特征,写出你的猜想,并证明你的猜想的正确性.
(1)根据上述规律,得到(n+1)?
=n+1+
(n≥1,n为正整数);
(2)等式左边=
=
,右边=
=
,
∴左边=右边,得证.
| n+1 |
| n |
| n+1 |
| n |
(2)等式左边=
| (n+1)2 |
| n |
| n2+2n+1 |
| n |
| n(n+1)+n+1 |
| n |
| n2+2n+1 |
| n |
∴左边=右边,得证.
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