![](https://wkrtcs.bdimg.com/rtcs/image?w=156&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"156","h":"96","dataType":"gif","c":"word/media/image1.png"})
s2=x2+y2+z2+(ict)2
ds2=-dx![](https://wkrtcs.bdimg.com/rtcs/image?w=12&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"12","h":"25","dataType":"gif","c":"word/media/image2.png"})
dx
d![](https://wkrtcs.bdimg.com/rtcs/image?w=13&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"13","h":"15","dataType":"gif","c":"word/media/image3.png"})
=
![](https://wkrtcs.bdimg.com/rtcs/image?w=33&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"33","h":"49","dataType":"gif","c":"word/media/image5.png"})
=0
A![](https://wkrtcs.bdimg.com/rtcs/image?w=11&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"11","h":"24","dataType":"gif","c":"word/media/image6.png"})
=
A![](https://wkrtcs.bdimg.com/rtcs/image?w=11&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"11","h":"25","dataType":"gif","c":"word/media/image8.png"})
=A
A![](https://wkrtcs.bdimg.com/rtcs/image?w=9&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"9","h":"24","dataType":"gif","c":"word/media/image10.png"})
=A
![](https://wkrtcs.bdimg.com/rtcs/image?w=15&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"15","h":"17","dataType":"gif","c":"word/media/image12.png"})
=
B=![](https://wkrtcs.bdimg.com/rtcs/image?w=27&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"27","h":"19","dataType":"gif","c":"word/media/image15.png"})
A
E=-![](https://wkrtcs.bdimg.com/rtcs/image?w=27&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"27","h":"21","dataType":"gif","c":"word/media/image16.png"})
-
B![](https://wkrtcs.bdimg.com/rtcs/image?w=8&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"8","h":"23","dataType":"gif","c":"word/media/image18.png"})
=-
E=ic(-)
J=(J,ic)
A=(A,)
![](https://wkrtcs.bdimg.com/rtcs/image?w=35&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"35","h":"21","dataType":"gif","c":"word/media/image25.png"})
-=-J
![](https://wkrtcs.bdimg.com/rtcs/image?w=33&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"33","h":"24","dataType":"gif","c":"word/media/image28.png"})
-=-
![](https://wkrtcs.bdimg.com/rtcs/image?w=25&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"25","h":"19","dataType":"gif","c":"word/media/image31.png"})
A+=0
F![](https://wkrtcs.bdimg.com/rtcs/image?w=17&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"17","h":"25","dataType":"gif","c":"word/media/image33.png"})
=-
F=
E=
B=+
![](https://wkrtcs.bdimg.com/rtcs/image?w=39&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"39","h":"48","dataType":"gif","c":"word/media/image39.png"})
=J
B=0
E=-
![](https://wkrtcs.bdimg.com/rtcs/image?w=39&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"39","h":"44","dataType":"gif","c":"word/media/image42.png"})
++=0
ｘ＇![](https://wkrtcs.bdimg.com/rtcs/image?w=13&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"13","h":"11","dataType":"gif","c":"word/media/image45.png"})
(ｘ-ｖｔ)
ｙ＇ｙ
ｚ＇ｚ
ｔ＇（ｔ－ｘ）
ｋ![](https://wkrtcs.bdimg.com/rtcs/image?w=8&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"8","h":"24","dataType":"gif","c":"word/media/image48.png"})
(ｋ－）
ｋ![](https://wkrtcs.bdimg.com/rtcs/image?w=11&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"11","h":"24","dataType":"gif","c":"word/media/image50.png"})
ｋ
ｋ![](https://wkrtcs.bdimg.com/rtcs/image?w=9&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"9","h":"25","dataType":"gif","c":"word/media/image52.png"})
ｋ
![](https://wkrtcs.bdimg.com/rtcs/image?w=16&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"16","h":"15","dataType":"gif","c":"word/media/image49.png"})
(－ｖｋ)
ｋ![](https://wkrtcs.bdimg.com/rtcs/image?w=20&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"20","h":"23","dataType":"gif","c":"word/media/image55.png"})
，ｋ
![](https://wkrtcs.bdimg.com/rtcs/image?w=140&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"140","h":"41","dataType":"gif","c":"word/media/image59.png"})
tan![](https://wkrtcs.bdimg.com/rtcs/image?w=116&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"116","h":"63","dataType":"gif","c":"word/media/image60.png"})
![](https://wkrtcs.bdimg.com/rtcs/image?w=12&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"12","h":"23","dataType":"gif","c":"word/media/image40.png"})
□
![](https://wkrtcs.bdimg.com/rtcs/image?w=12&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"12","h":"35","dataType":"gif","c":"word/media/image62.png"})
□A=-J
![](https://wkrtcs.bdimg.com/rtcs/image?w=12&md5sum=846e26237bf1231e412704e0687815b8&sign=2576fae53e&rtcs_flag=1&rtcs_ver=3.2&l=webapp&bucketNum=7&ipr={"t":"img","w":"12","h":"23","dataType":"gif","c":"word/media/image63.png"})
□
本文来源：https://www.2haoxitong.net/k/doc/b62651a00029bd64783e2cf3.html
文档为doc格式