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数学 高校生

右下の赤で囲っているところが納得できません。 どなたかよろしくお願い致します。

より、 01-18 (124) Step Up (p.CF-30) 9 AH-AB <PAB = 8 とすると、 25 このABCの外門の中心をPとする。 このとき, AP・AB ウ である。そこで あるのでB・AC[] である。 APAD MAC と表すと [エ n= [オである。 LA <180° より ∠A=120° したがって、 AB・AC=\AB||AC|cos120° 右の図のように、外心P から辺ABに垂線PHを引 くと、△ABPは AP-BP の二等辺三角形 において AB 3. BC=7. CA-3 とする. このとき > FAの内臓は内頭の図形的意味を考えて、 APAB(AP//AB/cose ABABAB 2.5-3 AB+AC BC_5+3³-7² 2AB・AC APcost=AH=AB AP=mAB + AC と表すと よって AP・AB=JAP|AB|cost = AB AP cose =AB=AB=AB²=25 =25m 第3章 平面上のベクトル AP・AB= (mAB+nAC・AB 15 2 = 5-3-(-4)= =m/AB+nAC AB 15 15 22m+9n 10m-3x=5① にして、 AP-AC-12AC-12 AP・AC= (mAB+nAC) ・AC =mAB.AC+n|AC|² 9 5m-6m=-32 Ist. 0. 829. m=13. n=-11 よって ② より 7 130 11552 I 120イ ウ 13 15 Jo このときの大きさは オ 8 1 2 から求める。 | BCP を ABとACで 先にABAC を求めてもよい ▼Pは外心だから, AP=BP=CP [cose の値を求めなくて 積の図形的意味を考えて、 |AB|| AP | cose =AB・APcosd=AB・A と変形できる. DA-a この点に関 ∠PAC=0 とすると、 AP AC =|AP||AC|cost' |AC|| AP|cost =AC AC=AC 8 9 平面上に四角 AP C が成り立ってい <考え方> 点Pが四角 すべての点 点Pは平面上の任 BA DA=0 同様にして,点Pz AB-CB0 よ 点Pが点Cに一致 BC・DC0 よ 点Pが点Dに一致 AD・CD=0 よ ①.②③ ④ より 逆に、四角形ABCI AP-CP-AP ( =lAPI BP-DP (AP JAP =APP より, AP・CP=BP・L よって, 四角形AB |OA|=3. LOB (1) cose の値を (2) 点Aから直 KLをOA <考え方> (1) OA (2) 直角三角 (1) OA-20B|=4 10A-20B JOA ①に代入して よって, cose:

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数学 高校生

解説の中段 ❗️[1]の部分について 先に問題文から2a>0が分かっているのに、答えの範囲として0<aを書く必要はあるのですか? この場合絶対にa>0成り立ちませんか?

284 基本例題 189 文字係数の関数の最大・最小 88 00000 ただし、 [類関西大] 関数f(x)=x-3ax2+5a0≦x≦3における最小値を求めよ。 a>0とする。 CHART SOLUTION この問題では最小値の候補となる極小値をとるxの値(本問ではx=2a) がαの グラフ利用 極値と端の値に注目 最大・最小 解答 f'(x)=3x²-6ax=3x(x-2a) f'(x)=0 とすると x=0, 2a a>0 であるから 2a>0 f(x) の増減表は次のようになる。 0 値によって変わるから, それが区間 0≦x≦3に含まれるかどうかをαの値によ って場合分けする。 [1] 02a≦3 すなわち [1], [2] から f'(x) f(x) 3 ...... + <a をとる。 20 極大 5a³ V 3 2 3 Kas 2 y=f(x)のグラフは右図 [1] のようになる。 よって, 0≦x≦3において, f(x)はx=2aで 最小値f(2a) = α² をとる。 0<a≦ 2a 0 極小 a [2] 3 <2a すなわち y=f(x)のグラフは右図 [2] のようになる。 よって, 0≦x≦3において, f(x)はx=3で 最小値f(3)=5α-27a+27 をとる。 のとき 0<a≦2/2 のとき x=2aで最小値 α, <a のとき += 基本 185 のとき x=3 で最小値 5²-27a +27 <-f(2a) (1) US-DUS =(2a)³-3a(2a)² +50² =8a³-12a³+5a³ =a3 [1] 極小値をとるxの が区間に含まれる場合 [2] 極小値をとるの が区間に含まれない場合 [1] y I 5a³ a () [2] y 5a³-27a+27 15a3 0 2a 3 32a 基本 a>0 (1) £ CHAE 4500 解答 y'=6x y'=0 yの増 また, (1) [ PRACTICE・・・・ 189 ③ をaを用いて表せ。 xの関数f(x)=-x²+ax^²-a の 0≦x≦1における最大値をg(α) とおく。 gall 881273 (岡山大 [2] (2) ④ [2] [3 ① P D

解決済み 回答数: 1
英語 高校生

教えてください!

列 f 3.重要 次の各組の2つの文がほぼ同じ意味になるように,( )に適語を入れなさい。 As he was sick, he could not attend the party. (1) (2) (3) (4) (5) (6) (7) (8) (9) Nancy got up and looked around. Nancy got up, ( ) around. Do you know a man whose name is Johnson? Do you know a man ) Johnson? The man who is sitting in the corner is my nephew. The man ( ) in the corner is my nephew. ) sick, he could not attend the party. My bag was stolen at the station. ( ) my bag ( ) at the station. Deeply shocked, I decided never to speak to her again. 1( To be frank with you, your essay is not interesting. Frankly ( ), your essay is not interesting. As it was Sunday, the shops were not open. It ( ) Sunday, the shops were not open. ). 4. 次の文中の適当なところに, 〔 〕内の動詞の分詞形を入れなさい。 (1) I could not make myself because of the noise. [hear] ) I was deeply shocked, I decided never to speak to her again. He stood there, folding his arms. He stood there, with his arms ( (2) I am very sorry to have kept you such a long time. [wait] (3) You should not keep your dog all day long. [chain) (4) Why don't you have your hair shorter? [cut) (5) Don't leave the water. [run) (6) There is no sugar in the pot. [leave) (7) The child returned to his parents. [lose] (8) Cars illegally will be removed. (park) (9) She spent a long time her garden neat. (make) (10) The children took turns rope in the yard. (jump) 〔高千穂大〕

未解決 回答数: 1
英語 高校生

2枚目の画像の赤線部分の 「A man that had his life enter the twists and turns that occur in all our lives, but in his case, the road stopped much too ... 続きを読む

次の英文を読んで, a~ f の 2 ]内の語(句) を正しく並べ替え, 本文中の 【 (1) 】 ~ 【(6) 】の適切な場所に入れなさい。 (a,bなどの記号は書かず,並べ替えた英文を記入するこ と) My first real job. Thirteen years since high school in training, in hospitals, in books. All of a sudden at 8 a.m. tomorrow morning I would suddenly become Dr. Dhillon. Time to heal and fix. I began my first real posting as a rural physician in a small town in rural Saskatchewan. A beautiful little hospital, staff happy to see a young doctor in town, and the welcoming red and green of the local Co-op sign. The day began innocuously enough: morning rounds at the hospital, learning about all the patients who had been handed over to my care for the next two weeks; trying to decipher other physicians' illegible writing and promising to never let mine get that bad, and failing quickly at that. C "Hello, good morning. My name is Dr. Dhillon and 【 (1) little while until your doctor is back." With a vague idea of what was actually happening inside each patient's body, and not a clue what was happening in their minds, I popped in from room to room as 【 (2) 】 of things to check and recheck after the morning ward round was done.//Thankfully, the nurses were there to handle any miscues and give me a vital, two-to-three-sentence summary of the patient and any concerns before entering into their realm with a quick knock on a half-opened door. When I got to the last patient I was to see that morning, I found his door was closed. It was at the back corner of the hospital. It was darker. "This is Gary, he's dying." The nurse's tone of voice lowered, naturally, to the level we use when discussing death, just in case death was nearby and would hear and come hither to hasten the process. "Metastatic, it was too late when he came in. Really sad story. He's still so young." She continued. I gently knocked, lighter, more gently 【 (3) 】 a gall-bladder attack whom I had just chatted to. "Hello Gary, how are you this morning?" is what I said. "Hello, who are you?" he asked. "My name is Paul and I'll be your doctor until your normal doctor comes back." I couldn't bear to say I was Dr. Dhillon. What was I going to doctor in his case? "I'm leaving on Tuesday. Next week. To be closer to home," he said. "That's great, so that's something to look forward to then." Inside, I wondered, Was that

解決済み 回答数: 3