单选题若级数收敛，则必有A．α＞In3．B．α≠1．C．D．a＜ln3．

单选题设A为n阶实对称矩阵，B为n阶可逆矩阵，Q为n阶正交矩阵，则下列矩阵与A有相同特征值的是

单选题设A，B为实对称矩阵，则A合同于B，如果

单选题下列说法中错误的是______(设D(X)≠0，D(Y)≠0)．

单选题设f(x)为已知连续函数，，其中s＞0，t＞0，则I的值______A.依赖于s和t．B.依赖于s．t，x．C.依赖于t和x，不依赖于s．D.依赖于s，不依赖于t．

单选题与矩阵合同的矩阵是

单选题Twenty-seven years ago, Egypt revised its secular constitution to enshrine Muslim sharia as "the principal source of legislation". To most citizens, most of the time, that seeming contradiction-between secularism and religion-has not made much difference. Nine in ten Egyptians are Sunni Muslims and expect Islam to govern such things as marriage, divorce and inheritance. Nearly all the rest profess Christianity or Judaism, faiths recognised and protected in Islam. But to the small minority who embrace other faiths, or who have tried to leave Islam, it has, until lately, made an increasingly troubling difference. Members of Egypt's 2,000-strong Bahai community, for instance, have found they cannot state their religion on the national identity cards that all Egyptians are obliged to produce to secure such things as driver's licenses, bank accounts, social insurance and state schooling. Hundreds of Coptic Christians who have converted to Islam, often to escape the Orthodox sect's ban on divorce, find they cannot revert to their original faith. In some cases, children raised as Christians have discovered that, because a divorced parent converted to Islam, they too have become officially Muslim, and cannot claim otherwise. Such restrictions on religious freedom are not directly a product of sharia, say human- rights campaigners, but rather of rigid interpretations of Islamic law by over-zealous officials. In their strict view, Bahai belief cannot be recognised as a legitimate faith, since it arose in the 19th century, long after Islam staked its claim to be the final revelation in a chain of prophecies beginning with Adam. Likewise, they brand any attempt to leave Islam, whatever the circumstances, as a form of apostasy, punishable by death. But such views have lately been challenged. Last year Ali Gomaa, the Grand Mufti, who is the government's highest religious adviser, declared that nowhere in Islam's sacred texts did it say that apostasy need be punished in the present rather than by God in the afterlife. In the past month, Egyptian courts have issued two rulings that, while restricted in scope, should ease some bothersome strictures. Bahais may now leave the space for religion on their identity cards blank. Twelve former Christians won a lawsuit and may now return to their original faith, on condition that their identity documents note their previous adherence to Islam. Small steps, perhaps, but they point the way towards freedom of choice and citizenship based on equal rights rather than membership of a privileged religion.

单选题设连续型随机变量X的概率密度f(x)为偶函数，且则对任意常数

单选题设函数f(x)有二阶导数，且,则(A)f(0)是f(x)的极大值．(B)f(0)是f(x)的极小值．(C)(0，f(0))是曲线y=f(x)的拐点．(D)f(0)不是，(x)的极值，(0，f(0))也不是曲线y=f(x)的拐点．

单选题设矩阵A与B相似，则必有 (A) A，B同时可逆或不可逆． (B) A，B有相同的特征向量． (C) A，B均与同一个对角矩阵相似． (D) 矩阵λE-A与λE-B相等．

单选题设函数f(x)为连续函数，并设x→0时F(x)～Axk，则(A，k)为______A．B．C．D．

单选题设为______．A．B．C．D．

单选题设函数f(x)在x=x 0 处存在三阶导数，且f"(x 0 )=0，f"(x 0 )=0，f"""(x 0 )=a＞0，则