A.相關(guān)系數(shù) B.付氏級數(shù) C.拉氏變換 D.付氏變換
A.不變 B.擴展 C.壓縮 D.僅有相移
A.x(t)=〡asinω0t〡 B.x(t)=7cos20t+6sint C.x(t)=3cos20t D.x(t)=〡cos20t〡