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圖片參考：http://img22.imageshack.us/img22/2275/16398264.jpgIn the figure, an advertising signboard DC is attached on a vertical wall and it is 8 m above the groung.A is a point 18m away from the foot of the wall B, where A and B are on the same horizontal ground.If the angles of elevation of the top and the bottom... 顯示更多 圖片參考：http://img22.imageshack.us/img22/2275/16398264.jpg In the figure, an advertising signboard DC is attached on a vertical wall and it is 8 m above the groung. A is a point 18m away from the foot of the wall B, where A and B are on the same horizontal ground. If the angles of elevation of the top and the bottom of the signboard from A differ by 10 , find the height of the signboard DC.
最佳解答:
tanㄥCAB = 8/18 ㄥCAB = 23.9624889... So ㄥDAB = 23.9624889...+ 10 = 33.9624889... So (DC + 8) / 18 = tan 33.9624889... DC = 4.124m(3 dec.)
其他解答:
tan/CAB=8/18 /CAB=23.96248897 tan/DAB=DB/18 tan33.96248897=DB/18 DB=12.124106301 So DC=DB-8 =4.124106301m
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F.3 maths Trigonmetry2發問:
圖片參考：http://img22.imageshack.us/img22/2275/16398264.jpgIn the figure, an advertising signboard DC is attached on a vertical wall and it is 8 m above the groung.A is a point 18m away from the foot of the wall B, where A and B are on the same horizontal ground.If the angles of elevation of the top and the bottom... 顯示更多 圖片參考：http://img22.imageshack.us/img22/2275/16398264.jpg In the figure, an advertising signboard DC is attached on a vertical wall and it is 8 m above the groung. A is a point 18m away from the foot of the wall B, where A and B are on the same horizontal ground. If the angles of elevation of the top and the bottom of the signboard from A differ by 10 , find the height of the signboard DC.
最佳解答:
tanㄥCAB = 8/18 ㄥCAB = 23.9624889... So ㄥDAB = 23.9624889...+ 10 = 33.9624889... So (DC + 8) / 18 = tan 33.9624889... DC = 4.124m(3 dec.)
其他解答:
tan/CAB=8/18 /CAB=23.96248897 tan/DAB=DB/18 tan33.96248897=DB/18 DB=12.124106301 So DC=DB-8 =4.124106301m
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