最佳回答取２０分：二條Trigonometric Relations問題

👨🏻‍🏫 學術台數學

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2007-05-23 3:19 am

1.Given than tan x = 3,find the value of sin x by using
trigonometric identities.
2.If tanβ = n, by using trigonometric identities, express
4sinβ+3cosβ/cosβ – sinβ in terms of n.
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更新1:

我本書個問題係咁喎我諗佢唔會出錯掛

更新2:

To:香港請寫出你計算的步驟=]

回答 (4)

[匿名]

2007-05-28 12:40 am

✔ 最佳答案

1.Given than tan x = 3,find the value of sin x by using trigonometric identities.

Ans:3/√10

2.If tanβ = n, by using trigonometric identities, express 4sinβ+3cosβ/cosβ – sinβ in terms of n.

Ans:4n + 3/1 - n

希望幫到你啦

參考: By 明智光秀

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DANNY

2007-06-19 10:40 pm

自問自答

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用戶130263

2007-05-23 3:48 am

1. x=71.6° ; sin 71.6°=0.949

2. (4n+3)/(1-n)

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cyw00009

2007-05-23 3:41 am

1.tan x=3
sin x/cos x=3
cos x=1/3‧sin x

sin^2 x + cos^2 x = 1
1/9‧sin^2 x+sin^2 x=1
sin^2 x=9/10
sin x=3/√10

2007-05-22 20:57:59 補充：
Q.2 has some problems...When β=45(degree),cosβ – sinβ=0, then the fraction would become meaningless...

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