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数学 高校生

数IIの不等式の証明の問題です。 黄色マーカー部分が分からないのですが、 (1)は、平方完成のやり方(特に今回のような分数が出てきた時)と、等号成立がどの場合か分からないので、教えてほしいです。 (2)は(1)と同じく、等号成立の求め方が分からないので、教えてください。 よ... 続きを読む

P +c から各 を考える。 【例題 169 不等式の証明 [2] [頻出] 次の不等式を証明せよ。 また, 等号が成り立つのはどのようなときか。 (1)x2+y≧xy+x+y-1 (2)a0b>0, a+b=1 のとき ax2+by2≧ (ax-by)2 (1) 目標の言い換え 条件式がない (左辺) (右辺) ≧0を示す ) 2 ≥ 0 ( )+( Action» 2次の不等式の証明は, (左辺) (右辺) を平方完成せよ 不等式の等号成立条件は,式変形の最後の式で考える。 2 0 をつくる。 思考プロセス 符号を調べ 右辺を因数 大数の符号を 等号成立 ... = ( )2 ≥ 0 ... = ( )²+( )2 ≥ 0 ) ≥0 = 0 のとき =0 かつ = 0 のとき = 0 または 式と証明 (左辺 (右辺)=x2+y2-xy-x-y+1 = x2 -(y+1)x + y - y + 1 = (x − x+1)²= (x + 1)² + 1 4 +y2-y+1 =(x+1)+33-6y+3+ 2 y+1 4 = (x-±1)² + 3(-1)² 20 4 = 0 のとき - (左辺) (右辺) を xにつ いて整理し, 平方完成す る。 残りの項を,yについて 整理し,平方完成する。 つのは よって x2+y2 ≧xy+x+y-1 はx-y= y+1 = 6 または これは x= かつ y = 1 である。 証明するだ すなわち, x=v=1のとき等号成立。 A, B が実数のとき A' + B2 ≧ 0 の等号が成立するのは, A=B=0 のときである。 (2)a+6=1 より b=1-a B<C する a > 0, 6>0 であるから 0<a<1 C = Cad = 100 (左辺) (右辺)=ax2+by2-(ax-by)2 =α(1-a)x2+2abxy+6(1-b)ye =α(1-a)x2+2a (1-a)xy+ (1-a)aye = ax + by - ax2+2abxy beye io 2000= =α(1-a)(x2+2xy + y2 ) b2 = a(1-a)(x + y)² 0<a<1より, α(1-α) > 0 であるから a(1-a)(x+y)² ≥0 よって ax2+by2 ≧ (ax-by)2 これは,x=-yのとき等号成立。 となる実 対称性を維持して a+b=1より 1-a=6,1-b=a を代入し, ab(x + y) と 変形してもよい。 |α(1-4) (x+y)2において α(1-α)>0より x+y=0のとき等号が 成立する。 きか

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英語 高校生

2を教えてほしいです💦お願いします🙇

英語 ( 70分) 1 次の文章を読んで 1~7の問いに英語で答えなさい。 It's Christmas Eve, December 24, 1914. The night is clear and cold/ Moonlight illuminates the snow/covered land separating the British and German trenches outside a small town in northern France. British military command feeling nervous sends a message to the front lines: it is thought possible the enemy may attack during Christmas or New Year. Extra caution will be maintained during this period. The military command has no idea what's really about to happen. Around seven for eight in the evening/ British soldier Albert Moren blinks in disbelief What's that on the other side? Lights flicker on./ one by one. Lanterns. he sees, and torches, and... Christmas trees? /"Stille Nacht, That's when he hears it - soldiers singing in German/" heilige Nacht." Never before had the Christmas music sounded so beautiful. I shall never forget it," Moren says later. It was one of the highlights of my life. Then, in response, the British soldiers start singing The First Noel." The Germans applaud, and counter by singing "O Tannenbaum." They go back-and-forth for a while, until finally the two enemy camps sing "O Come, All Ye Faithful" in Latin, together. "This was really a most extraordinary thing." soldier Graham Williams later recalled, "two nations both singing the same Christmas music in the middle of a war." Events just north of a small town in western Belgium go further still. From the enemy trenches, Corporal John Ferguson hears Someone call out, asking if they want some tobacco. "Come towards the light," shouts the German. So Ferguson walks out into no-man's land into the field between both armies. "We were soon speaking as if we had known each other for years." he later wrote. "What a sight little groups of Germans and British talking together almost as far as the eye can seel Out of the darkness we could hear laughter and see lighted matches.... Here we were laughing and chatting to men who only a few hours before we were trying to kill!" The next morning. Christmas Day, the bravest of the soldiers again climb out of the trenches. Walking past the barbed wire, they go over to shake hands with the enemy. Then they wave "come on!" to those who'd stayed behind. "We all cheered." remembered soldier Leslie Washington of the Queen's Westminster Rifles. "and then we all came out together like a football crowd." (A Gifts are exchanged. The British offer chocolate, tea and cakes: and the Germans share cigars, sauerkraut and schnapps. They make jokes and take group photographs as though it's a big./happy reunion/ More than one game of football is played./using helmets for goal posts. One match goes 3-2 to the Germans, another goes to the British, 4-1. In northern France/the opposing sides hold a joint burial service. "The Germans formed up on one side." Lieutenant Arthur Pelham- Burn later wrote./"the English on the other, the military officers standing in front, helmets off, heads bowed in respect. As their friends are laid to rest friends killed by enemy bullets - they sing in English "The Lord is My Shepherd" and the same song in German mein Hirt" their voices in unison. "Der Herr That evening, there are Christmas dinner parties up and down the lines. One English soldier finds himself invited into the German held zone to a wine cellar, where he and a soldier from southern Germany pop open a bottle of 1909 French champagne. The men exchange

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