高等数学IIB-2.doc

高等数学IIB-2高等数学IIB一、单项选择题(只有一个选项正确,共6道小题),则  (A) 1/2  (B) 2  (C) 1/4  (D) 4你选择的答案: D  [正确]正确答案:D解答参考:(2,1,2)点的法向量为()  (A) (1,4,-1)  (B) (1,0,0)  (C) (1,4,1)  (D) (-1,2,0)你选择的答案: A  [正确]正确答案:A解答参考:,则  (A) 1/3  (B) 2/3  (C) 1/4  (D) 3/4你选择的答案: C  [正确]正确答案:C解答参考:,则  (A)   (B)   (C)   (D) 你选择的答案: C  [正确]正确答案:C解答参考:  (A) 0  (B) 1  (C) 2  (D) 3你选择的答案: D  [正确]正确答案:D解答参考:  (A)   (B)   (C)   (D) 你选择的答案: B  [正确]正确答案:B解答参考:(注意:若有主观题目,请按照题目,离线完成,完成后纸质上交学****中心,记录成绩。在线只需提交客观题答案。)二、主观题(共7道小题)7. 设,则,求参考答案:解:代入可得:                                                          所以                                                                        8. 设,而,求参考答案:解:代入可得:                                                                     9. :解:由                                                                和                                                                 得                                                                                                                                                                                                                                                                                所以                                                                      且                                                                            故                                                                是极大值。10. 求函数