写简单的研究报告

y=x(140-2x)-20(140-2x) 满足P(A+B)=P(A)+P(B)不一定是互斥事件 已知函数F(X)=lnx-1/2ax^2-2x(1)当a=3时,求函数F(X)的最大值 （2）若函数F(X)存在单调递减区间求a取值范围 用vb 编写一个乘法口诀表 要求分别有四种三角形的形状 若tanα/2=(√5-1)/2,则sin2α-cos2α= Li Ming speaks English very well,_____________.(他确定如此,Tom也是）根据中文填英文 his sister speaks english very well的疑问句对very well的提问我自己觉得应该是how well does his sister speak English。这个可以吗？ 厄。。我想要的是最标准的。。 在△ABC中,tanA+tanB+√3=√3tanAtanB,且sinAcosA=3/4,判断△的形状 Please read English( )every morning.选项只有A, a few time. B.a few times C .few times I read English every day 已知|a+b+1|+a的2次方b的2次方+4ab+4=0,求-2a的2次方-2b的2次方的值 多项式4x²+1加上一个单项式后,使它能成为一个整式的完全平方,单项式为_______(有5个解) tom can speak english,___ ___?(完成反义疑问句) 1.Tom often teaches English at school.一般疑问句并作肯定或否定回答2.They often play the vidin after school.一般疑问句并作肯定或否定回答 Tom can speak English.(该为否定句） ---Tom ____ ____English. DO you read English every day 如何改为被动语态 do you read a (报纸) in english every day? Is you reading English every day?（对还是错）和Do you read English every day?有什么区别啊?两者应该用于什么? How long do you read English every day?怎么回答? You'd better read English every day(改为祈使句）（ ）English every day,( ). 若1/2a的2次方b+M=1/2ab(N+2b)则M=____,N=_____解题过程 几何数学题：已知:如图,在ΔABC中,AB=AC,AD⊥BC于点D,E是AB的中点,连结DE,求证:ED‖AC 若1.3*10的N次方X的A次方Y的4次方-125X的5次方Y的B+1次方=5X的5次方Y的4次方,求|2A-2B-N|的值? 圆X^2+Y^2-2y=3上的点到直线x-y-5=0的距离的最大值为（）选项A.3√2+1 B.3√2+2 C.3√2-2 D.3√2-1 如图,三角形ABC中,AB=2AC,点D平分边BC且AD垂直于AC,则角BAC=?度请尽量用全等三角形解答. 如图,在△ABC中,AB=2AC,AD平分边BC,AD⊥AC,则∠BAC= he read English every day.we go to schoolwe （go）to school from Monday to FridayMike （go） to school from Monday to Friday 用动词的适当形式填空 1.I like ____________ (swim).2.He _________(read) English every day..He _________(read) English every day.3.We _________(go)to school at seven in the morning.4.Mike________(go)to school at seven in the morning.5.My moth 设y=ax^15+bx^13+cx^11_5(abc为常数)当X＝7时,Y＝7,则X＝－7,Y的值为? 高中不等式证明题本人比较懒就用相机照下来啦~ 证明不等式（中学题）现有一组分数列是（1/10）^2+（1/11）^2+（1/12）^2+……+（1/1000）^2试证明该数列是大于0.099且小于0.111的. 请证明不等式：(a1+a2+...+an)^2/(a1*b1+a2*b2+...+an*bn)