【简答题】平面束的方程A 1 x+B 1 y+C 1 z+D 1 +λ(A 2 x+B 2 y+C 2 z+D 2 )=0是否包含所有过直线 的平面.
【简答题】已知平面向量 a =( x 1 , y 1 ), b =( x 2 , y 2 ) ,若 | a |=2,| b |=3, a ? b =-6 ,则 x 1 + y 1 x 2 + y 2 =______.
【简答题】通过点(1,-1,1)作垂直于两平面x-y+z-1=0和2x+y+z+1=0的平面高等数学复旦大学出版第三版下册课后习题答案 通过点(1,-1,1)作垂直于两平面x-y+z-1=0和2x+y+z+1=0的平面.
【简答题】在平面直角坐标系中,点集A={(x,y)|x 2 +y 2 ≤1},B={(x,y)|-1≤x≤1,-1≤y≤1},则点集Q={(x,y)|x=x 1 +x 2 ,y=y 1 +y 2 ,(x 1 ,y 1 )∈A,(x 2 ,y 2 )∈B}所表示的区域的面积为( )。
【单选题】— _____ — He is a bank clerk. [ ]
A.
Why does he like koalas?
B.
What does your father look like?
C.
Where is your father from?
D.
What does your father do?
【多选题】下列属于运力选择不当的不合理运输的是()
【单选题】Why does the man dislike living in the city?
A.
Because he like traveling.
B.
Because he does not like the house and neighbors in the city.
C.
Because he works near the country.
D.
Because he has a romantic attitude.
【单选题】Why _________ he like pandas?