[DSE 2019] 你地溫 數學 又溫成點呢？ [2]

Sorry ar, 上面冇x

不過應該可以試下分開兩題

問herman yeung 囉

手

d字幾靚

見在唔係你問我先寫
睇死你都係想拎答案去其他forum認叻

Thx

其實㩒 wolframalpha 就會出到嘅嘢 有咩好認叻

Uwants啲人仲未認得呢個usersname咩

咪鬼用個sir字形容佢啦

我覺得佢有時唔係好聽人講
其實唔少人唔止一次話過佢教out C嘢
但佢好似見唔到咁
跟住出mock又亂咁出 section A出non-foundation topic
不過無可否認佢係好有心嘅

個integrand 響個closed interval 入邊係bound 仲要continuous, 點可能in 唔到?

Rationalization of denominators + partial fraction

x/(x+Sqrt(1-x^2))
= x(x- Sqrt(1-x^2)) / (x^2-1)
x^2/(x^2-1) + x/(sqrt (1-x^2))

The result is then obvious

typo

Manipulation error!

(x+Sqrt(1-x^2)) (x - Sqrt(1-x^2))
= x^2 - (1-x^2) = 2x^2 - 1

Now x/(x+Sqrt(1-x^2))
= x(x- Sqrt(1-x^2)) / (2x^2-1)
= x^2/ (2x^2-1) + xSqrt(1-x^2)/ (1-2x^2)
= x^2/ (2x^2-1) + xSqrt(1-x^2)/ ((1-x^2) + x^2)
= x^2/ (2x^2-1) + 1/[((1-x^2) + x^2 )/ xSqrt(1-x^2)]
= x^2/ (2x^2-1) + 1/[Sqrt(1-x^2)/x + x/Sqrt(1-x^2)]

之後唔識

不如柒少陣當幫忙？

呢樣真
今年P1Q19a又係 死都要用 distance between a point and a line 嗰條式

其實已經有人講咗今年呢條用咗會扣分 佢都知咗
係咪應該拍過第二條片呢？
同埋bii part有人講返個正路方法 佢又唔講返喎

佢比我感覺係眼高手低 與其搞其他科 不如改善下數學啲片先

bii嗰度 我估佢係用當時最初諗到個方法拍 無花時間諗係咪好方法

眼高手低我認為就未至於
只係呢樣嘢見到佢未去到超勁嗰種層次咁解

今日有學生話我啲卷唔夠難

咁佢係咪真係做啱晒先

大半做到啦
但佢哋好似真係期望更難

有啲吃力