huainianmuqinzhongqiliangdeyuanyin

4a的平方+12ab+9b的平方-25 一列火车由静止从车站出发做匀加速直线运动,一位观察者站在这列火车第一节车厢的前端,经过10s,第一节车厢全部通过,则前九节车厢经过多长时间可从观察者身边全部通过?第九节车厢通过 不等式ax2+bx-1＞0的解集为｛x|3＜x＜5｝,则ab= 1.额定功率80KW的汽车,在平直的公路上行驶的最大速度为20米每秒,汽车的质量为2000千克,如果汽车从静止开始做匀加速直线运动,加速度大小为2米每秒平方,运动过程中阻力大小不变,求（1）汽 设二次不等式ax2+bx+c>0的解集是(-1,1/3)则ab=? ∫∫（x²＋y²）ds ∑:z=根号x²+y²被z=2所截得部分 ∫∫下面还有 ∑ 是好人就进来看下啊 求教! 我初一初二英语没学到,谁能归纳一下初一初二的英语语法知识.还有解题方法,反正是关于提高英语的求好人 1.在你一天的假期你打算干什么?What are you going to do ___ ___ ___ ___?2.My father likes doing outdoor sports.(同义句替换）My father likes doing ____ ____.3.Yesterday I went to my uncle's house.Yesterday I went to my ___. 1.He ate three bowls of rice for his lunch.(划线部分为three bowls of )________ _______ _______ did he eat for his lunch?2.I talk to him when I am in trouble.(划线部分为when I am in trouble)_______ ________ you talk to him?3.The poor man has 1.I _______(leave) in a minute.I _______(finish) all my work befoe I _______(leave)2.What ______ you _______(study) in our country?3._______ I _______(get) you a copy of today's newspaper?4.Mike _________(believe,not) this until he ______(see) it wit 《春日》[描写一下诗中的景色] 春的古诗,注：是描写春天景色的古诗——————? 根号下X方加一-2X＝4是二元一次方程吗 二元一次方程:(1)p(p-2)=5 (2)(6x-1)^2-25=0 (3)X^2=2根号2x-1 (4)(x-1)(x-3)=15 急!急!一元二次方程…… 函数y=x+1/(x+a)中心点是(—2,1)求a 当a>2时,函数 y=a^x 已知w=z(x^2+y^2) 求函数w在点1,1,2处全积分 什么叫全日照?并请解释一下为什么阳生植物都是全日照? 全日照什么意思? 描写春的诗句有哪些 若函数f（x）=logaX（0＜a＜1）在区间〔a,4a〕上的最大值是最小值的3倍,则实数a的值为 已知函数f(x)=(1-2a)x^3+(9a-4)x^2+(5-12a)+4a 若函数f(x)在区间〖0,2〗上的最大值是2,求a的范围0到2是闭区间,要讨论,估计麻烦点, 请告诉我一首关于春天的古诗 古诗春日的道理 1 The music will help ———（relax）.2 I have found that lost watch.（改为一般疑问句）.3 You should finish all your homework in half an hour .（in half an hour划线）(对划线部分提问)4 It has been famou for its theatres since 1._____（soon)or later.i will learn English well!2.we went to a lot of interesting places last year,we visited the White House____a.as well b.too c.either d.else3.The room is ____small that it can't hold 100 peoplea.very b.enough c.so d.quite4.Lots 1.The hunter is going t________ the forest.2.He often calls me _______ his mobile phone.(use)3.Animals ran ______(wild)everywhere.4.He ________ the earthquake luckily.He was one of the ___________(survive)5.In which d_______ are you going,north or so 问几道初二英语题目` 谢谢1.-How much would you ( ) me for this computer? -What about 5000 yuan? -Ok.I'll sell it to you.A.offer B.sell C.buy D.provide2.All the things in the supermarket are on sale.Mrs Liu bought a lot this morning,an 分段函数f(x)=x^3 0≦x≦1 √x 1 设f(x)为连续函数,则积分 ∫[1/n,n](1-1/x^2)*f(1+1/x^2)dx=答案为0