8-2tanx=5sin2x
回答 (3)
2013-02-11 9:15 pm
✔ 最佳答案
8 - 2tanx = 5sin2x 8 - 2tanx = 5( 2tanx / (1 + tan²x) )(4 - tanx)(1 + tan²x) = 5tanx4 - tanx + 4tan²x - tan³x = 5tanxtan³x - 4tan²x + 6tanx - 4 = 0(tanx - 2)(tan²x - 2tanx + 2) = 0tanx - 2 = 0 or tan²x - 2tanx + 2 = 0tanx = 2 or no real roots since △ = (-2)² - 4(2) < 0x = 63.43494882° or 243.43494882° 
2013-02-22 7:43 am
睇下隻死狗幾咁快手，幾咁痴纏！心術不正的狼子野心，他無意作答但存
心破壞，確實攪攪震又無幫襯！
心破壞，確實攪攪震又無幫襯！
2013-02-16 10:37 pm
我沒有刪除，我的回答為什麼突然不見了？
收錄日期: 2021-04-13 19:17:19
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130211000051KK00055