观察下列砌钢管的横截面图：则第n个图的钢管数是_1（用含n的式子表示）._刷题宝

题干

观察下列砌钢管的横截面图：

则第n个图的钢管数是 ____（用含n的式子表示）.

上一题下一题 0.0难度选择题更新时间:2016-05-03 05:17:37

答案(点此获取答案解析）

3

2

n2+

3

2

n

同类题1

已知定义在R上的奇函数y=f（x）满足f′（x）＜2，则不等式f（x+1）﹣ln（x+2）﹣2＞e^x⁺¹+3x的解集为（）

同类题2

It's good to see foxes because they are ____during the night, and we can see them walking.

同类题3

—Why, Jack! Someone seems to have called you over there.
—Yes? I ________ that.

同类题4

When he was questioned about the necklace, he__________that he had ever seen it.

同类题5

人吞咽时，能防止食物进入气管的结构是（　　　）

小学学科试题库

初中学科试题库

高中学科试题库