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本帖最后由 王守恩 于 2021-7-30 19:09 编辑
\(答案是\frac{441}{\sqrt{442}},手工能解吗?!\)
1,\(\frac{a}{\sqrt{21^2-a^2}}=\frac{\sqrt{20^2-\big(a-\sqrt{29^2-a^2}\big)^2}}{a-\sqrt{29^2-a^2}}\)
2,\(\frac{a}{\sqrt{21^2-a^2}}=\frac{a-\sqrt{21^2-a^2}}{\sqrt{20^2-\big(a-\sqrt{21^2-a^2}\big)^2}}\)
3,\(a=\sqrt{21^2-a^2}+\sqrt{20^2-\big(a-\sqrt{29^2-a^2}\ \big)^2}\)
4,\(a=\sqrt{29^2-a^2}+\sqrt{20^2-\big(a-\sqrt{21^2-a^2}\ \big)^2}\) |
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