求f（t)=t2＋2t＋2的拉普拉斯变换。

已知点的运动方程为x=2t y=t2-t 则其轨迹方程为：A. y=t2 —t B. x=2tC.

已知动点的运动方程为x=t y=2t2 则其轨迹方程为：（ ）。（A）x=t2-t （B）y=2t

求f（t)=u（t－2)的拉普拉斯变换。

现有:classThread2implementsRunnable{voidrun(){System.out.print("go");}publicstaticvoidmain(String[]args){Thread2t2=newThread2();Threadt=newThread(t2);t.start();}}结果为:()

现有:classThread2implementsRunnable{voidrun(){System.out.print("go¨);}publicstaticvoidmain(String[]args){Thread2t2=newThread2();Threadt=newThread(t2);t.start();}}结果为:()

classThread2implementsRunnable{voidrun(){System.out.print("go");}publicstaticvoidmain(String[]args){Thread2t2=newThread2();Threadt=newThread(t2);t.start();}}结果为:()