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数学 高校生

(3)についての質問です。 どうしてaをこのように場合分けするのか教えて頂きたいです!お願いします!🙏

実戦問題 90 対数関数の最大・最小 aを正の定数とする。関数f(x)= (logs4x) (logs/14) + alog.x (1≦x≦32) について I (1) t = log2x とおく。 f(x) をもの式で表すと, f(x)=ア+イウ++ また,t の値のとり得る範囲は オsts [カである。 (2) a=2のとき, f(x)はx=キのとき最大値 (3) x2 におけるf(x) の最大値をM とする。 0<a<ス のとき M = al + るとき,定数aの値を求めると α = 解答 Key 1 (1) f(x) Key 2 = = (loga 4x) (logs (4) + alogix* (log24+log2x) (log24-log2x)+α・ である。 4t (2+t)(2-t)+a.. = -t° +2at +4 log2 log2x log2 32 すなわち (2) g(t) = -t + 2at + 4 とおく。 a=2のとき 1/1 1≦x≦2のとき, 各辺の底を2とする対数をとると 0 ≤ t ≤5 g(t) = -t+4t+ 4 = -(t-2)² +8 よって, g(t) は t = 2 のとき 最大値8 t = 5 のとき 最小値-1 スのとき M = タチ α- ツテであるから,M=13 と ここで (01-7 t = 2 のとき, log2x=2より t = 5 のとき, log2x=5 より したがって, f(x)はx=4 のとき log2xd log24 a= 4 (1) 085 0= (01- x=4 x=32 最大値8 x = 32 のとき 最小値-1 x=[ケコのとき最小値サシをとる。 (3) g(t) = -t²+2at + 4 = −(t− a)² + a² +4 (i) 0<a<5のとき TAM 右のグラフより t=α のとき M = a² +4 また, M = 13 となるとき a² +4 = 13 h a² = 9 0 <a < 5 であるから a = 3 (EXB)(C (ii) a≧5のとき 右のグラフより t = 5 のとき M=10a-21 また, M = 13 となるとき 17 10a-2113 より 5 これはα≧5を満たさない。 (i),(ii) より, M = 13 となるとき,定数aの値は a=3 e -1 2 g(t) (Ba²+4) 4 8 4 29112 Ag(t) <10a-21 02 15 Oa5 となる。 g(t) 5a 真数は正であるから 4 4.x > 0, >0, x¹>0 であるが, 1≦x≦32 より、 これらの不等式はすべて成り 立つ。 | a>1 のとき M<N⇔loga M < loga N AST-48 (S) y=logax⇔ x = a 区間 0<t<5に頂点が含まれ るかどうかで場合分けする。 XUAL 57

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英語 高校生

1枚目の本文に対する2枚目の問題の答えを3-イか3-ロで迷っているのですが、どちらが正解かわかりません。どなたか理由もあわせて教えてもらいたいです。 よろしくお願いします!

Omoiyari is said to be a key concept of the Japanese mentality. (Its primary meaning is the ability to imagine other people's feelings. Japanese people's good manners have often (2) been associated with it and reported in news articles. For example, Japanese soccer supporters cleaned up the stadium after the matches at the World Cup, actions that were praised by the foreign media. Some experts say the supporters' behavior is related to education in Japan, where children clean their classrooms every day. Another example was seen during the frequent natural disasters. Even in such situations, many people still kept calm and patiently waited in lines for emergency supplies. JANET [ 3-1 ] According to a survey by an organization to promote good manners in Tokyo, less than 30 percent of Tokyo residents think people in Tokyo have good manners. [ 3-□ ] For example, Tokyo residents notice bad manners on the train. (4)Some young people sit in priority seats and do not give sit (5). V₂ 1 up their seats to the elderly, and others put on makeup. [ 3-> ] In an effort to get the passengers to 52 act more (5), railway companies display posters, saying things such as, "Please line up and c wait your turn" or "Please switch your phone to silent mode while ( 6-a) the train." 5 [ 3-= ] Omoiyari is often seen in school mottoes and emphasized in moral education at school. Some of the values that students are ( 6-b) include respecting the elderly, helping those with disabilities, and keeping promises. Students also take turns (6-c) in charge of cleaning the classroom, serving lunch, taking care of plants and animals. In addition, volunteer clubs collect money for charitable organizations and members visit elderly people in nursing homes. In moral education class, students read stories and discuss the topics in them. The teacher facilitates the discussion and the students draw their own conclusions. (Nakaya, et al., Discuss the Changing World, Seibido)

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英語 高校生

2と3と5がわかりません。教えてください🙇🏻‍♀️

Reading TI ERG HOITOM .noM Cappadocia* is a famous area in Turkey. It has a lot of rocks with strange shapes. Most of the rocks are very large. Because they gigs looked so strange, people thought it was very bad (look) at them. Mor (1) But now many people enjoy (2) (look) at them. The area became a 5 World Heritage Site* in 1985. volqm A noinst boom zid Tere db Bi 15 alus Cappadocia is also famous for its underground cities. People lived A-43 thiw pnom ribliza iw ou jarit oon saso14. M HATEMOUR MOITATE under the rock mountains. The size of the cities is (3)unbelievable. One of the largest cities has about ten underground stories and the deepest floor is more than 100 meters underground. There were even 10 churches, schools and restaurants. These underground cities were found around 1960. Later, scientists found that tens of thousands of Christians were living in the cities about 2,000 years ago. At that revo shovel time, the Roman emperor* killed many Christians, so they ran away from Rome and lived there. the answers to (5) these mysteries. There are many mysteries* about Cappadocia. Because it is in the A-44 UCSEHORS esert, the area is very hot in summer and very cold in winter. So why did people decide (4) (live) in such a hard place? And what did they do in the large underground cities? Scientists are still looking for gabloo * Cappadocia 「カッパドキア (地名)」 Christian 「キリスト教徒」 Tia World Heritage Site [ the Roman emperor 「ローマ皇帝」 noffidable, sd Now 160 mystery [] 2 15分 Jovinent loorbe A 1253000 A A-42

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