Grade

Subject

Type of questions

Mathematics Senior High

赤線部のように分かるのはなぜですか?🙇🏻‍♀️

基礎問 77 中線定理 小 △ABCにおいて,辺BCの中点をMとし, AB=c, BC=2a, CA = 6 とおくとき (1) cos B を a, b c で表せ. (2)AM を a, b c で表せ. (3) AB'+AC2=2 (AM2+BM2) が成りたつことを示せ . |精講 B M a b (2) 三角形の内部に線が1本ひいてあると, 1つの角を2度使うこ とができます. この問題でいえば,∠B を △ABC の内角と考え て(1)を求め,次に △ABMの内角と考えて(2) を求めることがそれ にあたります。 (3)この等式を中線定理 (パップスの定理) といいます。この等式は,まず使 えるようになることが第1です. 使えるようになったら自力で証明すること を考えることも大切です.また,証明方法はこれ以外に,三平方の定理を使 う方法や数学IIで学ぶ座標を使った方法, 数学Bで学ぶベクトル を使う方法などがあります。 HA 図中の線分 AM を中線といいますが,この線分AM を 2:1 に内分する 点Gを△ABCの重心といい (51), これから学ぶ数学Ⅱ の 「図形と方程 式」,数学Bの 「ベクトル」 でも再び登場してきます。 解答 (1) △ABCに余弦定理を適用して 4a²+c²-b2_4a²+c²-b² cos B= 2.2a.c 4ac (2)△ABM に余弦定理を適用して AM2=c2+α2-2cacosB=c2+a- 4a2+c2-62 2 62+c2-202 2 (3)a=BM,b=AC,c=AB だから, 2AM²=AC2+AB2-2BM2 よって, AB'+AC2=2(AM2+BM2)

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English Senior High

この黄色いマーカーのとこの分構造を教えて欲しいです。

異議をとなえる 明治大文 significant five per cent. 2022年度英語 7 chalerghg T困難だがやりがいある always prefer print to ebooks. By 2016, that number had climbed a modest but 控えぬ The increased sales books) and their popularity with of younger people, demonstrate that old media is not just the province the old)/ 領域 3 The argument that printed books were becoming outdated and obsolete was by challenged not only by books' renewed popularity, but also by expert studies that pointed out the psychological Benefits enjoyed by people (who liked to read 動 a remedy for (イ) b.difficult writing) (in other words researchers suggested reading ( n all sorts of problems) (2013) the journal Science published a study that concluded that people who mostly read literary writing had a clearer appreciation breached other people's ways of thinking than those who tended to prefer popular bestsellers: The authors (②this study) discovered readers to be better (あ the emotions expressed faces on at understanding others' false beliefs when they had just read prizewinning short stories than when they had I read lighter more commercial writing: This experiment provided a new contribution to the familiar debate (on the difference between literary writing and popular bestsellers Bluzin 1 0 experiment suggested b/captivated (②E a printed book) remained a worthwhile (even in the digital age that finding time to be activity (C① many people) O 4 est The view that people the past read more were better readers is not ✓ and (historical evidence. It is true that print experienced a golden age between the rise D mass audiences: ( the eighteenth century (and the twentieth- a century triumph of the paperback Nonetheless, well before competition (from social media, only a finy minority (①volumes that were published ever found a ader(1 Instead of reading novels carefully, aristocrats had their hair curled reader ✓ ever while listening to a servant reading aloud Long before people compiled favorite songs or pieces of music on their computer or mobile phone, poetry lovers scissored pages apart to paste scraps of one collection onto the margins of another. Early bookstores sold fish, while books were also sold door-to-door by clothing salesmen. Authors back then debated in print, as strongly as today's content providers do online, whether the written work should be rented or sold, licensed or owned. In short, printed books gave birth to many of the capacities cs CamScanner でスキャン

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