45. 若 為何? (A)20 sin(wt+45∘)( A ) (B)20 sin(wt-45∘) ( A ) (C)20 sin(wt+90∘) ( A ) (D)20 sin(wt) ( A )
45. 若 為何? (A)20 sin(wt+45∘)( A ) (B)20 s..-阿摩線上測驗