fxy二阶偏导数

我们放学后进行课外活动,翻译句子 _______ ________ do the _____ ______ after school 我们经常放学后踢足球.（翻译句子） We————afterschool. After school we always()(放学后我们总是过得很愉快） They usually piay volleyball in the playground after school.对in the playground after school提问 在学校英文翻译 什么时候用at school 什么时候用in school ,用法有何区别 学校里有个操场.there is a playground in the school.还是there is a playground at school.哪个对? 想象作文500字左右 求想象作文500字有一次考古学家挖掘出一只猛犸是坐着的前两只双腿是张开的 想象他变成化石之前在干什么 已知方程组3x=4+m 2y-m=5,则x与y满足的方程为（ ） A.3x+2y=1 B.3x-2y=1 C.3x-2y=-1 D.3x-2y=9 若tana=-2,则sina的平方-3*（cosa的平方）=? We have a big playground in our school.We all like to 1 games 2 after school.It’s Friday.We have only two classes 3 the afternoon.When school is 4 ,a lot of students go to the playground.Look!The boys of Grade Two are 5 a basketball match.Some girl 已知sina=2sinb,tana=3tanb,则(cosa)平方=?答案为1或3/8 We have a big library in our school .It is ___ than our classroom.There is ____in it.In the library there are a lot of story books _____ history and grography and many magazines.Some of them are for the students and some are for the teachers.We may _ 已知tana=3,sina的平方+sina乘以cosa=? we have lunch in a big —— （dine） hall at our school 用括号内所给词的适当形式填空 . We will have a big New Year's Party in our school tomorrow（改同义句）There __________ ___________a big New Year's Party in our school tomorrow we have a school day in our school (___ ___do you have in ___school?) 过直线X-2Y-Z=6=0,3X-2Y+2=0且与点（1,2,1）的距离为1平面方程 求直线x+2y-z+1=0 3x-2y+z-1=0在平面x+y+z-3=0上的投影直线方程.前面两个方程为直线方程组形式.x/3=(y-2/3)/0=(z-7/3)/-3 求过点(1,1,1)且垂直于平面x-y+z=7及3x+2y-12z+5=0的平面方程 I run in the playground with Wendy.（现在进行时） 在操场上打篮球的学生们打得多开心啊 ______________the students ________in the playground 李小龙的猛龙过江里,李小龙和那个中国女人在广场怄气时,来了一个意大利女人给李小龙抛媚眼!后来李小龙 布鲁斯·李 ﹦李小龙﹖ i always play tennis with my friends on the playground.in a word,i lovemy school life 怎么翻译? our school is behind a factory的同义句______ ______ a factory______ _______ _______our school.(将上题改为同义句） our schooL is behind house.求同义 1.The hotel is behind our school.改为同义句 Our school is______ ______ ______ the hotel2.A week has seven days.改为同义句_____ _____ seven days in a week.3.Is there a pen in your bag?（作肯定回答）____,_____ ______.4.one,two,pen,penc our schooL is behind house.求同义句 Our school is behind the parker（改为同义句) 夜空想象作文500字面对浩瀚的星空和皎洁的月色,你肯定也有过无穷的遐思和美妙的想象：或是神秘的仙境,或是动人的故事.请将它们写下来,一定能打动人 在前100个自然数之和中,将不能被3和4除净的数相加,和是多少.