困難對數函數問題 http://i707.photobucket.com/albums/ww74/stevieg90/IMG_6180_zpsqcv9l5ox.jpg?
回答 (1)
2014
x = ────────────────────────────────
(√2015 + 1)(∜2015 + 1)(⁸√2015 + 1)(¹⁶√2015 + 1)
Let ¹⁶√2015 = k , then
x = (k¹⁶ - 1) / [(k⁸ + 1)(k⁴+ 1)(k² + 1)(k + 1)]
x = (k⁸ - 1)(k⁸ + 1) / [(k⁸ + 1)(k⁴+ 1)(k² + 1)(k + 1)]
x = (k⁴- 1)(k⁴+ 1)(k⁸ + 1) / [(k⁸ + 1)(k⁴+ 1)(k² + 1)(k + 1)]
x = (k² - 1)(k² + 1)(k⁴+ 1)(k⁸ + 1) / [(k⁸ + 1)(k⁴+ 1)(k² + 1)(k + 1)]
x = (k - 1)(k + 1)(k² + 1)(k⁴+ 1)(k⁸ + 1) / [(k⁸ + 1)(k⁴+ 1)(k² + 1)(k + 1)]
x = k - 1
x + 1 = k
(x + 1)²º¹⁶ = k²º¹⁶
(x + 1)²º¹⁶ = ¹⁶√2015 ²º¹⁶
(x + 1)²º¹⁶ = 2015¹²⁶
2015ⁿ = 2015¹²⁶
n = 126
收錄日期: 2021-04-11 21:22:35
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160318081159AAKexbq
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