国民政府航空委员会

若二次方程有实根,则a是多少ax²-x+1=0x²-ax+1=0 二次方程 什么情况下 只有非正的实根 怎么求X的二次方程是否有实根?方程4X^+4KX+K+2=0 我不明白它的判别式：▷=（4k)^-4*4(k+2)>=0?即16（k+1）*（k-2）>=0 ▷的公式是什么? learn right from wrong 已知代数式（2mx的平方-x的平方+3x+1)-[-(-5x的平方+4y的平方）+3x]的值与x无关,求3m的 平 方-[2m的平方-(4m的平方+5)+m]的值 Learn to tell right from wrong when surfing the computer如何翻译 ______,he can't tell right from wrong exactly.A.as a young man B.Being young 为什么选 B 求过(-7,-3)并且有-4和1这两个根的二次方程解析式! 三元二次方程组解答y^2=x^2+136+x^2=r^2(r-y)/2=5/y I will been to school to learn Enlish. right or not ? 二次方程至多有一个正根如何限定 如果一个二次方程有两个同号的根,会有什么结论? 求函数y=logx^2-1底(x^2+2x-3)的定义域 TO OUR THE PQST IS BLACK AND WHITE BUT the future is always color 是什么意思? he can not tell black from white 已知函数f(x)的定义域为（0,+无穷大）,且满足f(2)=1,f(xy)=f(x)+f(y),又当x2>x1>0时,f(x2)>f(x1).若有f(x)+f(x-2)小于或等于3成立,求x的取值范围、、 To me,the past is black and white,but the future is always color. It is not always so easy to tell the white _____the black.A：between B：instead of C：from D：against 函数y=logx-1的3-x次方的定义域是多少 环境卫生,该重视打扫还是保洁【辩论赛】 观点是保洁. 2读加2书加2必加2须加2努加2力等于2000中,不同的汉字代表不同的数字,并以此从大到小的排列,那么,读、书、必、须、努、力应分别是什么?要算式 (辩论)环境保护是打扫重要还是环保重要? 请问：掌握2000个汉字,相当于应读完小学几年级? To like a person is not wrong,it is wrong to like a person who does not like you.前面的"to"是什么用法? Like a person is not wrong,it would be wrong in like a dislike themselves. If the person you like doesn't like you,Wouldn't it still be lonely even if the whole world loves If the person you likedoesn't like you,Wouldn't it still be lonelyeven if the whole world loves you? It is wrong ( of you to talk ) to your father like that .为什么这样做 you the wrong person for my love. 什么意思 It is wrong of you to laugh __________ people.A. at others B. in other C. at other D. in another why? 英语作文关于书写的重要性 （书写的重要性）英语作文怎么写我马上要 She was angey when she found the door was locked.She was angry _____ _____ the door was locked.