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[数列] 三角函数和数列一题

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longma Posted 2016-5-30 15:29 |Read mode
Last edited by hbghlyj 2025-4-6 04:16函数 $f(x)=\sin \omega x(\omega>0)$ 的图像在 $y$ 轴右边的对称轴与其交点从左向右依次记为 $A_1, ~ A_2, ~ A_3, ~ \cdots, ~ A_n, ~ \cdots$ ,在点列 $\left\{A_n\right\}$ 中存在不同三点 $A_k, ~ A_t, ~ A_p$ ,使得 $\Delta A_k A_t A_p$ 是等腰直角三角形。将满足上述条件的 $\omega$ 值从小到大组成的数列记为 $\left\{\omega_n\right\}$ ,则 $\omega_{2016}=\boxed{\frac{4031 \pi}2}$

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游客 Posted 2016-5-30 20:10
直接求出数列通项公式就可以了。

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 Author| longma Posted 2016-5-31 05:46
如何求出通项公式,求过程,谢谢!

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游客 Posted 2016-5-31 09:26
Last edited by hbghlyj 2025-4-6 04:27\begin{aligned}
&\mathrm{BD}=2, \mathrm{AC}=(2 \mathrm{k}-1) \mathrm{T},\\
&\triangle \mathrm{ABC} \text { 是等腰直角三角形。 }\\
&\Rightarrow \omega=\frac{2 \pi}{\mathrm{~T}}=\frac{(2 \mathrm{k}-1) \pi}{2} .
\end{aligned}

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敬畏数学 Posted 2016-5-31 09:41
回复 5# 游客
收藏此题及解法!好题好解法!

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 Author| longma Posted 2016-5-31 10:03
回复 5# 游客

我原来是在纠结最高点和最低点,能否构成斜边,现在想想是不可能的,如果两个最高点或两个最低点,构成斜边,那就没问题了

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