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数学 高校生

AをBに CをDにする方法がよくわかりません。 1番右上の塁上は約分できるということでしょうか。

f(0) >0 かつ y=f(t) の軸に f(0) ① が異なる2つの正の 解をもつための条件は, 右の図から D>0 かつ B・C =6 2つの店もある。「 ①の判別式をDとすると D=(2a)²-(3a+1)=4a²-3a-1 =(4a+1)(a-1) f(t) = t2+4at+3a +1 とする。 4204 451 412 42 等号が成り立つのは,2-34-2=2202 すなわち a=2 のときである。 よって, x+yの最小値は 2 であり シス -5 q= したがって ゆえに(赤<金(金) 解答編 63 +4 y=s\n 205 対数の計算) - CHECK- 208 (指数関数と対数関数のグラフ) 小数第10位 1 (1)与式 -/1/10g52+ log5(2.53) 2 gol 820 log,53 1 =2- ついて 2a>0 t=-2a D> 0 から (4a+1)(a-1) > 0 よって a< −, 1<a f(0) > 0 から (2) (5) Hols A log222 log222 110g52+ log52 +3 3 log232 よって、 関数 y=1 f(x)=(1/2) とすると (3)=(32) -STEP- =f(x) ニア3 のグラフと関数 y=l == し + log233+ log23 log232 log222 対称である。(①) のグラフはy軸に関して 0 ...... ... ② 21 また、関数 y= 3a+1>0 05 log 23 log23 (310g2310g23) のグラフと関数 3 1 ・410g23=12 y=logx のグラフは よって a> ③ 3 log23 直線 y= x に関して対称 1 2a>0から a<0 ④ 206 (大小関係) である。 ② y=log ~④の共通範囲を求めて 1 10/1 (1) log35 = = log75= = log53' log57 1 カキ -<a<- +-10Sapp *3 0<10g53 <log57 んであるから 209 (対数方程式・不等式) 1 1 累乗根を含む連立方程式) TRIAL- よって log,5 <log35 y=aの両辺を2乗すると 1 80log57 log53 したがって,大きいのは 10g35 (1) 真数は正であるから x-30 かつ よって x>3 ...... ① 方程式は 10gg(x-3)= 10g(x-1) log39 x2y3=a2.......① ① log₂24 -=bの両辺を3乗すると +1+( (2) log424 = = log224=10g2√24, = ゆえに log24 3 .... 2 3=10g22310g28 10g39 2 であるから 210g(x-3)=10g(x 10g(x-3)=log(3 したがって(x-3)=x-1 すると x2-7x+10=

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英語 高校生

「But reading isn’t just a nice thing to do – it’s an essential skill,something you need for everyday activities, whether that’s finding o... 続きを読む

Phil Hello. This is 6 Minute English from BBC Learning English. I'm Phil. Beth And I'm Beth. Are you a big reader, Phil? Phil Sure, I enjoy reading - and it's also a great way to pass the time on my daily commute to work. But reading isn't just a nice thing to do - it's an essential skill, something you need for everyday activities, whether that's finding out the news by reading a newspaper or buying groceries by reading the labels. Beth And that's why I was shocked by a recent UN report estimating that around the world over 700 million adults are illiterate, which means they can't read or write. Phil Wow! That's a huge number of people excluded from doing basic day-to-day things. So, what can be done to get more adults reading and writing? In this programme, we'll be hearing about projects in two very different countries trying to do just that. And, as usual, we'll be learning some useful new vocabulary as well. Beth But first I have a question for you, Phil. I mentioned a recent UN report on the high numbers of people unable to read and write, but illiteracy is not a new problem. Since 1967, the UN has been highlighting the importance of literacy, being able to read and write, with a day of celebration called International Literacy Day. But when does it take place? Is it: a) the 8th of March? b) the 8th of June? or, c) the 8th of September? Phil I think International Literacy Day is on the 8th of September. Beth OK, Phil, we'll find out if that's correct at the end of the programme. The biggest reason people grow up illiterate is not going to school, and that's especially true for people living in the coastal towns of Bangladesh. Because these towns flood regularly, families are always on the move, making it hard for children to get an education. Phil The Friendship Project teaches reading and writing to groups of Bangladeshi women and girls. They also teach numeracy which means the ability to do basic maths like counting and adding up. Here one student, Rashida, explains the impact it's had on her to BBC World Service programme, People Fixing The World: Rashida My parents never sent me to school and I've suffered from not being able to read and write. My children were embarrassed that I was illiterate. I couldn't even do basic accounting. Until now, I've had to use my fingerprint as a signature as I was illiterate, but now I can sign my name because I can read and write thealphabet, and I'll also be able to keep an account of my expenses. No one can cheat me anymore. Beth Before the Friendship Project, Rashida couldn't write her signature – her name written in her own handwriting. Instead, she had to use her fingerprint. Now, Rashida has learned the alphabet and also some basic maths, so she knows how much money she's spent, and how much she has left. This means no-one can cheat her, can trick or swindle her into taking her money.

解決済み 回答数: 1
数学 高校生

なぜ|k|/5と表せるのでしょうか?

28 よ 不等式 x+ys4,y20 を同時に満たす実数x, yについて, -3x+4y のとり得る値の最大値、 最小値を求めよ。 POINT 3x+4y=k とおくと, これは直線を表す。 この直線を動かし、 直線-3x+4y=kが2つの不等式の 表す領域と共有点をもつときのkの最大値と最小値を求める。 解答」 x2+ye4y0 を同時に満たす領域をD とすると,Dは、 右図の斜線部分 (境界線 を含む)となる。 領域は半円の周および内部 となる。 -3x+4y=k... ① とおくと, ① は傾きが 3 3 k ①はy= -x+ 4 4 2 x で,切片がの直線を表す。 領域と最大最小の考え方 岡 について動画で理解! 求める値は, 直線 ①が領域 Dと共有点をも ときのんの最大値と最小値である。 図より (i) 直線①が点 (2,0) を通るときは最小となり k=-3x+4y=-3・2+4・0=-6 (i) 直線①が円 x+y=4…② の y> 0 の部分で接するとき, kは最 大となる。 ここで,円②の中心 (0, 0) 直線①の距離をd とすると |-3.0+4.0-k| |k| d= = √(-3)2 +42 5 |k| 直線 ①が円 ②に接するとき =2 5 すなわち k = ±10 直線①が円②のy> 0 の部分で接するのはk=10 のときである。 (i), (ii)より, -3x+4yの最大値は 10, 最小値は6・・・ 箸 回回 円と直線が接するときであるか ら (円の中心と直線の距離) = (円の半径) を利用する。 (例題 3 参照)

解決済み 回答数: 1