急! F4 Basic Trigonometry ex

2012-10-21 7:36 am

請詳細步驟教我計以下三條:
(不要綱址回答)

Solve the following equations, where 0度<=x<=360度

1. tan3x=1.732
2. sin2x=0.348
3.cos x/3=0.7651

回答 (1)

2012-10-21 11:36 am

✔ 最佳答案

1)
tan 3x =
圖片參考：http://www4a.wolframalpha.com/Calculate/MSP/MSP95081a3e5ad3dd0446fd00001fg3iche2285ehfh?MSPStoreType=image/gif&s=61&w=25&h=20

3x = 60 , 240 , 420 , 600 , 780 , 960
x = 20 , 80 , 140 , 200, 260 , 320

2)
sin 2x = 0.348
2x = 20.365 , 159.635 , 380.365 , 519.635
x = 10.183 , 79.817 , 190.183 , 259.817

3)
cos 3x = 0.7651
3x = 40.084 , 319.916 , 400.084 , 679.916 , 760.084 , 1039.916
x = 13.361 , 106.639 , 133.361 , 226.639 , 253.361 , 346.639

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