2.1 KiB
2.1 KiB
Fact
Text
Cards of this note wil be created in {{c1::Default::which deck ?}}
Fact
Text
Cards of this note wil be created in {{c1::English::which deck ?}}
The English Language
Vocabulary
Item vocab idioms
Front
(it's) raining cats and dogs
Back
it's raining very hard
Grammar grammar
Item
Front
说出名词从句的形式
Back
- that + 一个完整的句子, that无实际意义
- 由疑问句改装而成
Computing
Item lisp emacs programming
Front
How to trap errors in elisp ?
Back
(condition-case the-error
;; the protected form
(progn
(do-something-dangerous)
(do-something-more-dangerous))
;; handlers
(error-symbol1 (handler1 the-error))
((error-symbol2 error-symbol3 (handler the-error))))Math
Item1
Text
The dot product of two vectors is {{c1::$|\alpha| \cdot |\beta| \cos{\varphi}$}}
Extra
Item2
Front
Given two vectors:
\begin{equation*} \alpha = \{a_1, a_2, a_3\}, \beta = \{b_1, b_2, b_3\} \end{equation*}What's the result of $\alpha \cdot \beta$ ?
Back
\[a_1b_1 + a_2b_2 + a_3b_3\]