在平面直角坐標(biāo)系中，曲線的參數(shù)方程為（為參數(shù)），在以原點(diǎn)為極點(diǎn)，軸的正半軸為極軸的極坐標(biāo)系中，曲線的極坐標(biāo)方程為，射線的方程為，又與的交點(diǎn)為，與的除極點(diǎn)外的另一個交點(diǎn)為，當(dāng)時，．

（1）求的普通方程，的直角坐標(biāo)方程；

（2）設(shè)與軸正半軸的交點(diǎn)為，當(dāng)時，求直線的參數(shù)方程.

設(shè)對于任意實(shí)數(shù)，不等式恒成立.

（1）求的取值范圍；

（2）當(dāng)取最大值時，解關(guān)于的不等式：．

若復(fù)數(shù)為純虛數(shù)（i為虛數(shù)單位），則實(shí)數(shù)a的值是

A．-3               B．-3或1            C．3或-1            D．1

已知映射,其中A=B=R，對應(yīng)法則，若對實(shí)數(shù)，在集合A中不存在元素x使得，則k的取值范圍是

A．           B．           C．            D．

（   ）

A．              B．           C．              D．

已知函數(shù)滿足，其圖像與直線的某兩個交點(diǎn)的橫坐標(biāo)為的最小值為，則

A．                        B．

C．                        D．

的展開式中含有x的正整數(shù)冪的項(xiàng)的個數(shù)是

A．0                B．2                C．4                D．6

設(shè)都是銳角，且，，則=（ ）

A．            B．            C．或     D．或

在棱長為2的正方體中，點(diǎn)E,F分別是棱AB,BC的中點(diǎn)，則點(diǎn)到平面的距離等于（ ）

A．              B．            C．            D．

已知，，，點(diǎn)C在內(nèi)， ，若=2m+m（），則=（    ）                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         

A．1                B．2                C．             D．4