cos
cos — 連接詞
1. used in informal speech or writing instead of 'because' to introduce the reason
因為
口語中代替because
used in informal speech or writing instead of 'because' to introduce the reason why something happens or why someone does something
Owen stayed home from school cos he had a high fever and a sore throat.
Owen 因為發高燒又喉嚨痛,所以待在家裡沒去上學。
cos + clause stating the reason
Kemi was smiling all afternoon cos she got the scholarship she applied for.
Kemi 整個下午都笑瞇瞇的,因為她拿到了申請的獎學金。
We ordered takeaway for dinner cos the kitchen was being repainted all day.
我們晚餐叫了外送,因為廚房一整天都在重新粉刷。
João can't join the video call cos his internet connection keeps dropping out.
João 沒辦法加入視訊通話,因為他的網路一直斷線。
文法句型
cos + clause stating the reason
用法筆記
Common in casual texting, notes, and everyday conversation. Avoid 'cos' in formal essays, business writing, or academic papers — use 'because' or 'since' instead.
常見錯誤
cos — 名詞
1. in mathematics, a value from 0 to 1 that is found by dividing the length of the
餘弦
數學中cosine縮寫
in mathematics, a value from 0 to 1 that is found by dividing the length of the side next to a specific angle by the length of the longest side in a right-angled triangle
Sora calculated cos 30° by dividing the adjacent side by the hypotenuse.
Sora 將鄰邊除以斜邊,算出 30 度的 cos 值。
cos + of + angle for the cosine function
Liang used a scientific calculator to find the cos of 60 degrees for the exam.
Liang 用工程用計算機算出 60 度的 cos 值,以準備考試。
The teacher wrote 'cos 45° = 0.707' on the board and asked the class to check it.
老師在黑板上寫下「cos 45° = 0.707」,請全班同學驗算。
Rodrigo checked the cos of 90 degrees on his calculator and wrote down the answer.
Rodrigo 用計算機檢查 90 度的 cos 值,然後寫下答案。
- cosine
the full form of the word; used in formal writing and in speech
文法句型
cos + angle
用法筆記
Used mainly in written mathematics and science. In speech, mathematicians usually say 'cosine' rather than pronouncing 'cos' as a separate word. The angle that follows is usually given in degrees (°) or radians.
常見錯誤
cos — 縮寫
1. the written form of 'cosine' placed before an angle value, such as cos 30° or co
餘弦簡寫
書寫用餘弦縮寫
the written form of 'cosine' placed before an angle value, such as cos 30° or cos θ, in mathematical equations and formulas
From sin² A + cos² A = 1, Putri found sin A when she knew cos A was 0.6.
Putri 利用 sin² A + cos² A = 1,在已知 cos A 為 0.6 的情況下算出 sin A。
sin² + cos² identity used to find an unknown value
Chiara wrote 'cos 30°' in her notebook and checked the result with a calculator.
Chiara 在筆記本上寫下「cos 30°」,並用計算機核對結果。
Saira used v = u cos θ to find the ball's forward speed at a 40° angle.
Saira 用公式 v = u cos θ 計算球在 40 度角下的水平速度。
To find the width of the river, Nkechi used cos 30° in her triangle calculation.
為了算出河的寬度,Nkechi 在三角形計算中用到了 cos 30°。
- cosine
the full written form; preferred in running text but identical in meaning
文法句型
cos + angle value
用法筆記
Standard notation in all branches of mathematics and physics. Always written in lowercase in modern textbooks. When typing on a computer, 'cos' is used exactly as it appears in print.