【简答题】已知f是直角坐标平面xOy到自身的一个映射,点P在映射f下的象为点Q,记作Q=f(P),设P 1 (x 1 ,y 1 ),P 2 =f(P 1 ),P 3 =f(P 2 ),…,P n =f(P n-1 ),…。如果存在一个圆,使所有的点P n (x n ,y n )(n∈N*)都在这个圆内或圆上,那么称这个圆为点P n (x n ,y n )的一个收敛圆。特别地,当P 1 =f(P 1 )时,则...
【简答题】Every morning I lay on the floor in the front parlour watching her door. The blind was pulled down to within an inch of the sash so that I could not be . When she came out on the doorstep my heart...