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数学 高校生

赤い線が引いてあるところで、xで割るのにx=0の時と0でない時で場合分けしていないのはなぜですか?教えてください!

例題 221 定積分と すべての実数xについて, 等式 xf(x)=x+2 f(x) を求めよ。 思考プロセス « Re Action 上端 (下端)が変数の定積分は, 定理の利用 y=f(x) とおくと ★★☆☆ +2 ff(t) dt を満たす関数 af*f(t)dt=f(x) を利用せよ 1910 Go Ah 微分方程 でその現 探究 例題 薬を血 さで代 をxで微分する + xf'(x) =1+2f(x)⇒y+xy'=1+2y f(x) し、 微分方程式 にx=1 を代入 1・f(1)=1+2ff(t)dt 0 () iA 解 xf(x) = x+2 2* ƒ (t)dt ... ..① とおく。 163 よって, ②より 両辺を積分すると=fa ①の両辺をxで微分するとf(x)+xf'(x) =1+2f(x) dy y = f(x) とおくと x =y+1 dx ... ② 関数 f(x) はすべてのxについて定義されており, 定数関数 f(x) = -1 は等式① を満たさないから, x(y+1) ≠0 としてよい。 1 dy 1 y+1dx x 両辺をxで微分して微分 方程式をつくる。 dx f* f (t)dt = f(x) リ Ac 関数 f(x) = -1 のと (笑)き、①の左辺は x 右辺は 2∫(-1)dt 脚生 (1) 思考プロセス (1) If (2) はっ 血中 [条 条件 x+2 log|y+1| = log|x|+Ci =x-2(x-1) =-x+2 これより |y+1| = elog|x|+C1 = eCielog|x| = となり, f(x)=-1 は ① を満たさない。 よって y=±ex-1 C ここで,C=±e とおくと y=Cx-1(C≠0)ol 例題 1=C・1-1 より C = 2 したがって,求める関数 f(x) は f(x) =2x-1 Point... 微分方程式と初期条件 B4 また, ① に x = 1 を代入すると f(1) =1であるから, らf(1)=1 ff(t)dt = 0 であるか t (2) t 微分方程式の一般解は, 任意定数を含む 曲線群を表すが、これらの曲線のうち 点(x1, 21) を通るもの、すなわち x= x1 のとき y = yı 3) という条件を満たす特殊解は,いくつかに限定される。 微分方程式に対するこのような 条件を初期条件という。 ■ 221 すべての実数xについて L チャレンジ (7)

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英語 高校生

間違っているところがあったら教えてください🙇‍♀️

Despite (3) Please remember ( be waked 2 In spite of③Although ④But for ) me up at 7 o'clock tomorrow so I can get to school on time. 2 to wake 3 waking (4) Take this coat to the laundry. It's so dirty that it ( 1 needs to wash 2 has it cleaned 4 woke 3 needs washing ①wants cleaned (5) We are likely to have a warm winter this year for the first time ( ①in ten years ③ past ten years (6) ( 2 over ten years' period ①ten years ago ) asked Michael about the matter, he wouldn't say a word. ①Anyone 2 Even if 3 However ) me go out with Tom. 2 allow 3 prevent (7) My father would not ( 1 let (8) But ( ①against ). (東京経済大) (玉川大) (立教大) ④Whoever (摂南大) ④ resist ) the rain and cold wind, we would have had a nice holiday. 2 from 3 of ④ for (西南学院大) (昭和女子大) (9) Miki and her family ( ) out of town. I have called several times, but there is no answer. I could go (10) ( 1 Either 2 must be 3 should go ) it is fine or not, the football game will take place. 2 Neither 3 Though (11) It's ( ) that I'd like to take my dog for a long walk. would be (南山大) ④Whether (獨協医大) ①such a beautiful day 2 a so beautiful day 3 such beautiful a day a beautiful day so (高知大 (12)( ) will be elected as the next chairperson? ①Do you think who 2 Do you think whom 3 Who do you think ④Whom do you think (国士 1 a day (14) To read a foreign language is ( 1 few 2 one 2 at a day 3 other (13) Here's your medicine. Take one capsule three times ( ) thing, to speak it is quite another. 5 this ④some 3 by a day ), after each meal. ④for a day (東北学

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英語 高校生

間違っているところがあったら教えていただきたいです🙇🏻‍♀️

6 CD Chacal the 1 Choose the best answer to fill in the blanks. (1) (1) ( ) the editor of this magazine? ①Do you know is who 3 Who do you know is 2 Do you know who is Who is do you know (関西 (2) Please keep your eyes ( 1 close 2 closing ) until I tell you to open them. 3 closed 4 to close (京 (3) One of the twins lives in Tokyo, but ( ) lives in New York. ①another 2 other 3 the other 4 the others (4) There is not much hope ( 1 as 2 how ) they are still alive. 3 that 4 which (5) The language ( ①speaking (6) He ( 1 should ) in the province is Arabic. 3 spoke 2 speak ) be sick. I just saw him playing soccer. ③ can't ④spoken (月 (7) It will not be long 1 before 2 may ) we meet again. 3 above 2 on ④ won't SET ④during (8) Tom may not have studied ( 2 as hard ①enough hard (9) There are many books worth ( ) to pass the entrance examination. 3 hard enough 4 hard as ) more than once. 3 reading to be read 1 read 2 to read (10) James found ( ①him ) difficult to write down foreign names. 2 himself 3 it ④them (11) They suggested that he ( ) to the meeting. 1 come 2 comes (3) came 4 had come (12) Hurry up! Our bus is leaving ( ) a few minutes. I till 2 on 3 during 4 in (13) You will miss the train ( ) you walk more quickly. 1 if (14)( How about 2 without 3 unless ) take the train instead of the bus? It's faster. ②Let's 3 Why don't ④but for ④Why not

解決済み 回答数: 1