南充都京镇

设二次函数f(x)=ax^2+bx+c(a、b、c为常数）的导函数为f'(x),对任意X∈R,不等式f(x)≥f'(x)恒成立.则b^2/(a^2+c^2)的最大值为. 设计英文签名谁能帮我设计一个英文签名：Yann 2的-x次方=1/2的x次方 那到底是增函数还是减函数? f（x）=xe^x+ax^2+bx 在x=0和x=-1时都取得极值1.求a和b的值2.若存在实数x属于〔1,2〕,使得不等式f（x）《二分之一x^2+（t-1）x成立,求实数t的取值范围；一楼解错了 二楼第一个问对了下面的不详细 已知函数f(x)=ln(x+1)+ax若存在x∈[1,2],使不等式f'(x)≥2x成立,求a范围 迎战的英语单词是什么意思啊? 有关于高三导数的一道题目已知e为自然对数的底数,若对任意的x∈[1/e,1],总存在唯一的y∈[-1,1],使得lnx-x+1+a=y^(2)e^y成立,则实数a的取值范围是（）A.[1/e,e] B(2/e,e] C(2/e,+∞ ) 已知,如图,△ABC中,AB=AC,E是AC上一点,∠A=2∠EBC,求证BE⊥AC 英语翻译anomalous mole fraction effect characteristic of vertebrate Ca channels这句怎么译? 英语翻译CDR-H3 resides in the center of the P5a/P5c helical interface atthe three-helix junction (Fig.5A).Residues Gly-98,Ser-100,andThr100a interact with the wide and shallowminor groove of P5c viadirect H bonds,and Tyr-102 contacts P5a by H bon 哪里发生地震了 为什么要发生地震 一件衣服的原价是240元,现在降价五分之一,现价是多少元? 一道英语选择,说下选哪个,并说明理由The survey found that young people would improve their job prospects _______ they studied business studies,maths,English and physics or chemistry at A-level.A until B since C whereas D if 函数y=0.25的x次方减去0.5的x次方再加一是增函数还是减函数?看到的请速回~要说明理由~ 对于x大于等于1的一切实数,不等式2分之1【x-a】大于等于a都成立,则a的取值范围是【 】 这2道英语题为什么选这个?You___A_____him so closely;you should have kept your distance.A shouldn't have been following B.shouldn't followC mustn't follow D couldn't have been following Not until the game had begin__D____ at the sports groun 这道英语题为什么选这个答案?帮忙看看答案错没讲明原因,谢谢Don't worry.He is ______ to look after little Betty.A.carefully enough B.enough careful C.carful enough D.enough carefully 答案是C 我们班一个女生一直叫我爱妃是我什么意思啊（我是男的） 女同学叫男同学爱妃是什么意思? 男生叫女生爱妃是么个意思?他说我现在是她爱妃= =我们俩是同学额 英语翻译科学杂志上的：1.and Sloggett further suggest that our findings may instead be explained solely by the presence of harmonine in H.axyridis eggs.2.Is there enough evidence for intraguild predation on H.axyridis eggs?只告诉我那 Terence Koh是谁?中文名——许汉威有人知道他的一些具体情况么 我明天要参加校运会的3000米,请问要作什么准备?比如 比赛前能不能喝水等 明天就要校运会了800米如何跑得好我是初一男子 几道英语选择题目 最好说下理由 不说也没事1.In one year rats eat 40 to 50 times ____weight.A.its B.and C.their D.theirs2.It is one thing to enjoy listening to good music,but it is quiet_______to perform skillfully yourself.A.other B. 英语一道选择题说下理由Please keep me informed____the changes in case they affect our work.A.with B.for C.of D.by 已知直角三角形的周长是2+根号6,斜边长是2,则这个直角三角形的面积是? 多给些列题 一道英语选择踢 说下理由I called at ten yesterday ,but nobody answerd the phone.I at school then.A was studying B study C am studying D studied 一个英语选择题,并说下理由He is good at making jokes.He always has others____at his jokes.A.laughed B.to laugh C.laughingD to be laughed 已知函数f(x) x∈R f(1)=1 f'(x)