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数学 高校生

数学II指数対数 ピンクのマーカー部分が分かりません。 対数不等式の場合分けってどのような規則なんですか?

第11章 指数関数・対数関数 重要 例題 44 対数不等式 (2) 不等式 210gsx-410gx27≦5 ア <x≦ 198 POINT!」 √イ ウ 9 ...... ①が成り立つようなxの値の範囲は EGU H 対数不等式→まず (数)>0 対数の底の条件 (底)>0, (底) ¥1 不等式の両辺に同じ数を掛ける→ I <x≦ [オカ] である。 x>0 解答 真数は正であるから x>0 かつx≠1 は対数の底であるから 共通範囲を求めて x>0 かつx≠1 log327 3 ここで 10gx27= log3x log3x 3 2 文字を含む式を掛けるときは正か負かで場合分けする。 50<² E-S 1<x≦81 すなわち0<x<1のとき ------------------ 12 よって, ① から 210g3x --5≤0 log3x [1] 10g3x>0 すなわち x>1 のとき ②の両辺に10g3x を掛けて 2(10g3x)-510g3x-12≦0 すなわち (logsx-4) (210g3x+3)≦0 30 (pol-S 10g x>0より210g3x+3>0であるから 10g3x-4≦0 よって ゆえに x81 log3x≦4 " 9 x>1 との共通範囲は [2] log3x<0 ②の両辺に10g3 x を掛けて 2(10g3x)-510g3x-12≧0 すなわち (logsx-4) (210g3x+3)≧0 10g3 x<0より10g3x-4<0であるから 210gx+3≦0 よって 10g3x≦! ゆえに x≦ 0<x<1との共通範囲は 0< x≤ [1], [2] から 求めるxの値の範囲は √13 70< x≤ √√3 9 √3 ・正なら不等号の向きはそのまま。 負なら不等号の向きは変わる。 (4) 9800 1<x≦オカ 81 (2) CHART まず (数) > ◆(底)>0,(底) ¥1 ←logab= & logeb logca 両辺に掛ける数 10g3 x の 正負で場合分け logsx>0のとき不等号の 向きはそのまま 02-pol 02 -078 ELCO log3 x ≦log3 34 から x≦4 184 ◆場合分けの条件x>1との 共通範囲。 logsx<0のとき不等号の 向きは変わる。 logsx≦logs 3/12 から x23 12 基84 ◆場合分けの条件 0<x<1 との共通範囲。 gol=DES ① を考えよう。 (1) 練習 44 不等式10g10x+10g10 (x-2a) <10g10 (4-4a) (1) 真数は正であるから x>ア かつx> イウ かつαく エ ② から a≦オのときx>ア, オ<a<エ (2) ① の解は αオのとき カ<r< 2 のときx>イウ ...... 重 { C

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英語 中学生

長文読解なんですが、5と6を教えて欲しいです。 よろしくお願いします🙏

3 次の会話文と英文は, 拓也 (Takuya) と 彼の家にホームステイしている留学生の高校生マーク (Mark) と が話したときのものです。 1~7の問いに答えなさい。 Takuya : Hi, Mark. What are you reading ? Mark: I'm reading a letter from my sister, Emily. Takuya : Oh, really? How is she? Mark: She's fine. She's now studying to be A veteri...? What does it mean? A veterinarian. It means a doctor for animals. Oh, I see. I think it's a hard job. Does she like animals? Yes, she does. What (2 k Takuya : Mark: Takuya : Mark: Takuya : Mark: You can read this letter. Takuya : Really? Thank you. Takuya : Mark: Takuya : Mark: Takuya : Da Mark: Takuya : veterinarian. And she also loves nature. She joined a group she likes very much. ) of group did she join? Dear Mark, How are you? Are you enjoying your life in Japan ? I have big news. Three weeks ago, I joined a volunteer group ( 3 ). We usually go to mountains or rivers near our town and clean them, because birds and animals sometimes eat the garbage there. We know it is not good for them. Also, in winter, we will go to one of the lakes and see how many birds there are. I heard there were about 500 birds last year. I hope this winter we will see more birds than last winter. We only do small things, but I believe that doing small things is important. Last night, I told my grandmother about our group. She enjoyed listening to me. She loves flowers and birds very much, but she uses a wheelchair now. She doesn't go out very often to enjoy nature. Then I came up with an idea. I am going to ask our volunteer group to go hiking with people like her and help them. It will be (5 if we can do so! I think she will be 6 to go with us. I will write about it next time. (it) hard kitc Love, Emily 01 ** a ウ I 02 書 03 Oh, she's so nice. I think so, too. Is volunteer work popular in Japan ? Yes. There are a lot of people who are interested in it. I want to join a volunteer group that does something for nature like my sister. I've been thinking the same thing. My mother joined a group. Her group collects used kitchen oil and makes soap from it. Oh, it's good for nature. Do you think we can join the group? I don't know. Shall I ask her about it?

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