题目
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
提问时间:2020-10-30
答案
=(x^4+x^3y)+(y^4+xy^3)+(4x^3y+4x^2y^2)+(4xy^3+4x^2y^2)+x^2y+xy^2
=x^3(x+y)+y^3(x+y)+4x^2y(y+x)+4xy^2(y+x)+x^2y+xy^2
=-x^3-y^3-4x^2y-4xy^2+xy^2+x^2y
=-x^3-y^3-3x^2y-3xy^2
=-(x^3+x^2y)-(y^3+xy^2)-2x^2y-2xy^2
=-x^2(x+y)-y^2(x+y)-2xy(x+y)
=x^2+y^2+2xy
=(x+y)^2
=1
=x^3(x+y)+y^3(x+y)+4x^2y(y+x)+4xy^2(y+x)+x^2y+xy^2
=-x^3-y^3-4x^2y-4xy^2+xy^2+x^2y
=-x^3-y^3-3x^2y-3xy^2
=-(x^3+x^2y)-(y^3+xy^2)-2x^2y-2xy^2
=-x^2(x+y)-y^2(x+y)-2xy(x+y)
=x^2+y^2+2xy
=(x+y)^2
=1
举一反三
已知函数f(x)=x,g(x)=alnx,a∈R.若曲线y=f(x)与曲线y=g(x)相交,且在交点处有相同的切线,求a的值和该切线方程.
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
奥巴马演讲不用看稿子.为什么中国领导演讲要看?
想找英语初三上学期的首字母填空练习……
英语翻译
最新试题
- 1The sense of psychological
- 2如图,AB是圆O的直径,AC是弦,角BAC的平分线AD交圆O于点D,DE垂直于AC,交AC的延长线于点E.
- 399、58、201的最大公因数是多少
- 4求篇what have you learn in universerty English class
- 5关于不等式相加减的问题
- 61.Jack______(like)thrillers and action movies.2.Do you want______(go)to a movie?3.On_____
- 7用静组词,填入括号内.入夜,田野里一片().一条()的林阴小道...
- 8I made a model ship.She helped me.(保持意思不变)
- 9书店运来一批故事书.第一天卖出总数的30%,第二天卖出总数的35%,第二天比第一天多卖出25本.这批书一共有多少本?
- 10The doctor operated on the young boy at once and _____(save) his life.
热门考点