1. odd function -> let u = -x
2. natural log -> log (a/b) or log (ab) = log a +or - log b
3. Let function , check condition
4, product of 2 functions =>by parts
相聚離開都有時候2019-05-02 22:16:05
條matrix
唔夠guideline做 諗唔到
不過都執到啲分
紅色派對2019-05-02 22:35:00
其實(c) pure 都成日做
見A^-1 => 諗點砌個A such that A.A^-1 = I
呢個技巧pure 都係成日用
詳見AL Pure Maths Paper 1 2004 個一條matrix