设X~N(1.5,4),计算: ⑴P{1x<3.5}; ⑵P{x>5.5}; ⑶P{3.5<x<5.5}; ⑷P{∣x-3∣<6.5}。
曲线y=(x-l)2(x-3)2的拐点的个数为( )
By how much does the sum of the roots of the equation (x+1) (x-3) = 0 exceed the product of its roots?
What is the average (arithmetic mean) of x and y?
(1) The average of x+3 and y+5 is 14.
(2) The average of x,y and 16 is 12.
设直线 在平面∏上,而平面∏过点(1,-2,5)且垂直于直线(x-3)/2=(y-1)/(-4)=(z-2)/(-1),求a,b的值。
直线L:(x+3)/(-2)=(y+4)/(-7)=z/3与平面∏:4x-2y-2z=3的关系是( )。
曲线y=x2-2x+3与直线y=x+3所围成图形的面积S=()
将(x-6)(x-3)(x-8)展开为系数多项式的形式。
直线l:(x+3)/2=(y+4)/1=z/3与平面π:4x-2y-2z=3的位置关系为:()
直线L:(x+3)/(-2)=(y+4)/(-7)=z/3与平面∏:4x-2y-2z=3的关系是( )。