工程测试技术+习题答案.docx

第一章三、计算题x1TT0x(t)d t1TT2 xT00x sin t dt0T02 sin tdt2 xTT0 cos t 24x02 x00T1TTxrms0x2 (t )dt1TTx20x sin tdt2200TT 10cos2t2dtx021-3 求指数函数的频谱。解答：X( f)x(t)e j2 f tdt(a j2 f )tAeate j2 f t dt A e0(aj2 f) 0Aaj2 fA(aj2 f)a2(2 f )2X ( f )a2k(2f )2( f )arctan Im X ( f )Re X ( f )arctan 2fa|X(f)A/( f)/20f0f-