问题 选择题
已知曲线y=
x2
4
的一条切线的斜率为
1
2
,则切点的横坐标为(  )
A.1B.2C.3D.4
答案

已知曲线y=

x2
4
的一条切线的斜率为
1
2
,∵y′=
1
2
x
=
1
2

∴x=1,则切点的横坐标为1,

故选A.

单项选择题 A1型题
问答题

【程序说明】
本程序先从文件读人各考生的准考证号(设为整型数)及成绩,并将其存放在一棵检索二叉树上,二叉树结点的健值是成绩,每个结点带一链表,链表结点存放取得该成绩的考生的准考证号。然后,程序按中序遍历检索二叉树,从高分到低分输出结果,使每行输出成绩及其取得成绩的考生的准考证号。
【程序】
#include < stdio. h >
typedef struet idnode
int id;
struct idnode * next;
ldNode;
typedef struct marknode I
int mark;
ldNode * head;
struct marknode * left, * right;
MarkNode;
char fname [ ] = "sp07.dat";
main( )
int id, mark;
MarkNode * root = null;
FILE * fp = fopen(fname," r" );
if(!fp)
printf("file%s open error, \n" , fname);
exit(0);

while (!feop(fp))
fscanf(fp," %d%d", &id, &mark);
btree(&root, id, mark);

fclose(fp);
print(root);

btree(MarkNod * * mpptr, int id, int mark)
ldNode * ip;
MarkNode *mp = * mpptr;
if (1)
if (mark==p->mark) addldNODE ( (2) , id);
else if ( mark >mp -> mark) btree (&top -> left, id, mark);
else btree(&mp-> right, id, mark);
else
Imp = ( marknode * ) malloc(sizeo (marknode) );
mp -> mark = mark;
mp -> left =mp -> right = NULL;
(3)
addldNode(&mp -> head, id);
(4) ;


addldNode(ldNode * * ipp, int id)
ldNode * ip = * ipp;
if ( (5) )addldNode ( (6) ), id;
else
ip = (ldNode * )malloc(sizeof(ldNode) );
sp - > id = id;
ip -> next = NULL;
(7)


print(MarkNode * rap)
ldNode *ip, *ip0;
if (mp)
print ( mp -> left);
printf(" %6d: \t" ,mp -> mark);
ip = mp -> head;
while(ip)
printf(" %6d" ,ip -> id);
ip0 =ip;
ip = ip -> next;
free (ip0);

printf(" \n" ); printf( mp -> right); free(mp);