皮皮学，免费搜题
登录
搜题
【简答题】
若z=z+iy，试证： (1)sin z=sin x．cosh y+icos x．sinh y； (2)cos z=cos x．cosh y—isin x．sinh y； (3)｜sin z｜2=sin2 x+sinh2 y； (4)｜cos z｜2=cos2 x+sinh2 y．
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】Although it _________ in the desert most of the year, people still live there.
A.
doesn’t rain
B.
didn’t rain
C.
hasn’t rained
D.
hadn’t rained
【简答题】下面是三个婴儿的行为。玛丽在母亲离开丢下她一个人在房间里时,嚎啕大哭, 一位陌生人前来安慰,她很不情愿与之接近。母亲归来立即靠近,寻求接触,甚至带着眼泪作出微笑,情绪迅速平复好转,并主动与母亲一起玩耍。麦瑟林的表现则是另一番景象。母亲离开时似乎无动于衷, 转过脸径自拿起玩具玩耍起 来。陌生人走来也不回避,但一个人留在房间里时有些不安。母亲回来也没有显出高兴,甚至躲避与母亲接近,身体移开,目光转移,...
【单选题】He once worked out a plan for the project; ______, most people didn’t agree to it.
A.
then
B.
instead
C.
however
D.
but
【单选题】Most young people didn't receive enough financial education from their parents.
A.
Y
B.
N
C.
NG
【单选题】At the beginning of the twentieth century, most people didn’t accept Albert Einstein’ theory when it was first _______. [ ]
A.
put out
B.
put aside
C.
put down
D.
put forward
【简答题】新车在出售前，对车辆出厂年月、发动机号 、车架号 和外观的检查称之为（ ）检查。
【简答题】之前作业1-10没有交或者上传不成功的同学重新上传通道
相关题目：
【单选题】Most young people didn't receive enough financial education from their parents.
A.
Y
B.
N
C.
NG