皮皮学，免费搜题
登录
搜题
【简答题】
某调幅波表达式为u AM （t）=5（1+0.6cos2π*4*10 3 t）cos2π*465*10 3 t（v）画出此调幅波的频谱图，并求带宽。
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】Last time you your umbrella at school. Today you mustn' t ________ it any more. [ ]
A.
forgot; leave
B.
left; leave
C.
forgot; forget
D.
left; forget
【单选题】--- I forgot to do my homework. Don’t tell the teacher. --- I won’t tell anybody, but do you think you can _______ it?
A.
get away from
B.
break away from
C.
get away with
D.
run away from
【简答题】传播学是研究 及其运行规律的科学。
【单选题】—Tom, you never told me why you were late for school again,_____ you? —____ . But maybe you forgot it, sir.
A.
weren’t, No
B.
did, No
C.
did, Yes
D.
didn’t, No
【简答题】I was so busy yesterday that I forgot (call) ______ you.
【简答题】已知2 ≤|x| ≤3,则函数y=(x-1) 2 的取值范围是( ). (A)1 ≤y ≤4和9 ≤y ≤16. (B)1 ≤y ≤16. (C)4 ≤y ≤9. (D)1 ≤y ≤9.
相关题目：