Feb30th1712

This user can contribute with an advanced level of English.

この利用者は初級の日本語ができます。

該用戶的母語是中文。
该用户的母语是中文。

Currently reading 計算機概論第六版(ISBN 986-421-565-5).

Math

${\frac {d}{d\theta }}\sin \theta =\cos \theta$

${\frac {d}{d\theta }}\cos \theta =-\sin \theta$

${\frac {d}{d\theta }}\tan \theta =\sec ^{2}\theta$

${\frac {d}{d\theta }}\cot \theta =-\csc ^{2}\theta$

${\frac {d}{d\theta }}\sec \theta =\sec \theta \tan \theta$

${\frac {d}{d\theta }}\csc \theta =-\csc \theta \cot \theta$

$\cos 2\theta =\cos ^{2}\theta -\sin ^{2}\theta =2\cos ^{2}\theta -1=1-2\sin ^{2}\theta$

$\sin ^{2}\theta ={\frac {1-\cos 2\theta }{2}}$

$\cos ^{2}\theta ={\frac {1+\cos 2\theta }{2}}$