三角學(一D都唔明)

👨🏻‍🏫 學術台數學

[匿名]

2009-08-03 6:31 am

1.(tan²30∙sin²45)/(cos^²60 )

2.sin²45-cos²45+sin30X
cos60+tan60
呢D數點計數植架?我一D都唔明,麻煩各位解釋下,THX!!

回答 (4)

用戶7639

2009-08-03 6:54 am

✔ 最佳答案

As follows:

圖片參考：http://a.imagehost.org/0806/ScreenHunter_01_Aug_02_22_51.gif

2009-08-02 22:54:22 補充：
第2題唔可再打清楚d題目?!

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尹珮

2009-08-03 5:19 pm

http://img198.imageshack.us/img198/1779/37619922.jpg

(有啲角好似30, 45, 60係有特定的分數)
http://img29.imageshack.us/img29/2118/91806328.jpg

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用戶10012

2009-08-03 2:54 pm

To do this type of questions, you have to MEMORIZE the sin, cos and tan of the three special angles : 30, 45 and 60.

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石石

2009-08-03 8:06 am

I think he means:
sin²45-cos²45+sin30 * cos60 + tan60,
where " * " means "times"

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