四川冰川

如图,直线y=kx+b经过A（2,1）,B（-1,-2）两点,则不等式½x＞kx+b＞-2的解集为多少? 先后跑仍两枚质地均匀的正方体骰子(六个面分别有数字1.2.3.4.5.6)抛扔第一枚骰子得到的点数1.求点P落在直线Y=X上的概率2.求点P落在圆X的平方+Y的平方+25外的概率 matlab怎么添加函数想在matlab里面调用impseq函数,但是没有这个函数,需要自己添加, 证明在一个三角形中 a=b cosγ+c cosβa,b,c为三角形三边 αβγ为三边所对的三个角提示是：sin(α)=sin (π-β-γ)=sin (π-β)sinγ-sinγcos(π-β) 三角形中cos(A/2)^2 + cos(B/2)^2 + cos(C/2)^2 > 2 matlab 中总是提醒括号数不对,但我检查了好多遍都是对的啊.为什么c = [-n*H*(n+m)*[r_c*H^2+r*hu^2+r_s*hs^2-r*H*(alpha*hu+hd)]-m*H*(n+m)*[r_c*H^2+r*hd^2-r*H*(alpha*hu+hd)]-r_c*H^3*(n+m)*(m-n)+2*r*hu^3-r*hu^2*n*[3*H*(n+m)-2*hu*n]-2 求问Matlab关于括号对称的问题!小弟在用matlab编程的时候,想在矩阵里面定义一个方程的运算,f=@(x) 1/sqrt(1-(sin(alpha/2))^2*(sin(x.))^2)；但是系统总是显示：错误:圆括号或方括号不对称或异常.请问 matlab括号匹配s=(rs.*vs.*t^2/2+rz.*l.*t+((sqrt(2*rs.*rz.*l.*vs.*t+rz.^2*l.^2)).^3)/(3*rs.*rz.*l.*vs))/(2*rs.);总是提示我括号不匹配或缺失.这是怎么回事啊? matlab,输出怎么是括号呢》?、 已知集合A=｛x｜x²+3x+2 =0｝,B=｛x｜ax=1｝,若B是A的真子集,求实数a所构成的集合M并写出M的所有非空真子集 根据首字母提示完成短文 .one day jim was walking home after school.Suddenly,he saw his father's new car.TO his ___ ,the driver was not his father.It was young woman instead.'She must have ____my father's car ',he said to ____.下面还有 根据首字母提示,完成短文Dear Betty, I'm writing to tell you that i will move to London next week.My family p_____ to live there forever.I feel sad, because i will not be a____ to see you often. We always have a great time.We 根据首字母的提示完成短文 根据首字母提示,完成下面短文.Food is very important.Everyone needs to eat well if he orshe wants to have a s____ body.our minds also need a kind of food.this kind of food is knowledge.we begin to get knowledge even when we are very y_____ 关于英雄主题的文章文章篇名：_____________________________________主要内容：______________________________________________________________________________________________________________我的感受：_______________________________ 根据所给首字母提示完成短文 有关英雄主题的文章文章篇目、真正的英雄形象、我的感受 以英雄为主题的作文写对英雄的理解,和当今社会中是否需要英雄!再加点自己的见解!小弟在此谢过了!大家多多帮忙! f(x)=(3a-1)x+4a,x 12 12 24 ( )括号里应填什么为什么答案给的是14呢? 用所给的短文内容以及所给字母提示填空………帮帮忙 根据短文内容及所给的首字母写出单词.he 2008 Olympic Games are coming soon.Chinese people are getting r_____ for it.The people in Beijing are especially b_____.Taxi drivers are learning English so that they can t _____ with the foreign 根据短文内容和首字母写单词Everyone would like to go to Egypt for a vacation.When people 1.t____ there,one of their favorite places to 2.v____ will be the Pyramids.The biggest pyramid of all is the Great Pyramid of Khufu.This pyramid was 根据内容和所给的首字母补充短文.Look!This is my schoolbag.It's 1.o______ the sofa.That's my computer.It 2.i______ on the desk.Those are my keys.3.T______ are 4.i______ the bag.These are my books and pencil box.They are 5.u______ the tab 已知二次函数y=ax^2+bx+c的图象如图所示,给出下列结论①abc>0②b=2a③a+b+c0,其中正确的有哪些? 我24了 为什么还张个子了 我 现在当1.78了 矩阵的秩为r,有没有等于零的r阶子式 任何矩阵都有秩吗?那零矩阵呢? 设P,Q都是3阶非零矩阵,为什么“PQ＝0,所以,秩(P)＋秩(Q)≤3”,什么定理? 如图为一台两挡式电热水器的内部简化电路,R1和R2为两条不同的发热丝,S为温控开关,当S接a时电路中的电流为5A；当S接b时电路中的电流为0.1A．求：(1)R1的电阻（2）请通过计算说明开关接哪个 21.(x)是定义在R上的奇函数,当x≥0时,f(x)=2x-x2.21.(x)是定义在R上的奇函数,当x≥0时,f(x)=2x-x^2.(1)求x＜0时,f(x)的解析式.(2)问是否存在这样的正数a,b,当x∈〔a,b〕时,g(x)=f(x),且g(x)的值域为〔1/a ,1/b 〕 设函数f(x)是定义在R上的奇函数当x＞0时f(x)=x2-2x+3试求出f(x)在R上的表达式