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数学 高校生

(2)で底が一より小さいので不等号の向きが変わるのは分かるのですが、いつどのタイミングで変わるかがよく分かりません。どなたか解説お願いします🙇

202 第5章 指数関数・対数関数 練習問題 16」 次の方程式・不等式を解け . (1)(10g)+210g3x=0 (2) (logir)²-logir²-320 精講 t=logar という変数変換をすることで,2次方程式や2次不等式 に持ち込むことができる問題です.この変数変換では, には真数 条件により x>0 という制約がつきますが,こが x>0 の範囲を動くときに は, t はすべての実数値をとりうるので,tの変域には制約がつきません。 解答 (1) t=10g とおく. 真数条件より x>0 ….. ① (このときはすべての実数をとる.) 与方程式より,f2+2t=0, t(t+2)=0, t=0, -2 t=0 のとき logs=0 log3 = 10g33°⇔ x=1 t=-2 のとき logsx=-210g=log33-2⇔ x= r= -1/1 9 よって、x=1/11 1 (これらは ①を満たす.) (2) t=log} とおく.真数条件より 「x>0 かつ^>0」⇔x>0 …② (このときはすべての実数をとる.) 与不等式より,(10g/r)^-10g/x-3≧0 (logr)²-2logr-3²0 -2t-3≧0, (t+1)(t-3)≧0, t≦-1, 3≦t log}x≦-1,3≦log/ -1 logir ≤log (1), 32 (12) 11083(12) 10g/ log/ ≤ 底1/23は1より小さいので. I (21) (12) 2 ≧x 122, 121 8 ②とあわせて,0<xs/1/2≦x 8 31 O 8 _t=log/x 1 0<a<1のときは 不等号の向きが反転 する 2

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英語 高校生

15行目からどうしても訳せません。 訳教えて欲しいです🙇よろしくお願いします。

What would you do if you wanted to learn about something? A traditional way is to go to your bookshelf, pick up a dictionary or encyclopedia, and start turning pages. Now, however, you can turn on your computer, connect it to the Internet and start its search program. You just type in some keywords, click "search," and soon you will 5 have what you are looking for. 2 3) It seems as if anything you want to know can be found on the Internet. The range of information you can find on the Net varies from *gossip, to news, to the most advanced technological findings. Furthermore, the information is always fresh. New information is constantly added, past files are re-written, and *news reports are broadcast as they come in. 5) 3 What is being lost, though, is the joy of discovery. In many ways an Internet search is like a package tour. On a package tour, you generally know where you are going and see only what the *tour organizer has selected. Similarly, what you find in the Internet search is controlled by the site's owner or is the result of a computer program. On the other hand, turning the pages of an encyclopedia, as you look up an *entry, is more like wandering through a forest. You may accidentally find something interesting in the entry just next to the one you have been looking for. This may *stir up a new interest, which will eventually lead you into a totally different topic. 248 words>

解決済み 回答数: 1