学年

質問の種類

数学 高校生

問題にはα、βと書かれているのにmの条件を求めるところでD≧0となっているのはなぜですか? D>0では無いのですか??

18 例題 50 判別式と解と係数の関係 **** xについての2次方程式 x2-2mx+3m²-m-3=0の解α,βがとも に実数のとき,'+' の最大値、最小値とそのときの実数mの値を求めよ. 「考え方」解と係数の関係から+°をα+B,aßを用いてmの式で表すと+°はmの 2次式で表すことができる。このことから 2次関数の最大・最小の考えを利用する。 このときのとり得る値の範囲について考えなければいけないが,これは,与えら れた2次方程式が実数解をもつことから、判別式を利用する 解答 x2-2mx+3m²-m-3=0 ・・① とする. ①において,解と係数の関係より a+β=2m, aβ=3m²-m-3 であるから,一 a2+β°=(a+B)2-2 =(2m)2-2(3m²-m-3) =-2m²+2m+6 ax2+bx+c=0 (a≠0) の解α, βに ついて. α+B=b. a=c a' a 第2 + do 1 13 = m D また①の判別式をDとすると,実数解をもつから, D≧0 もとの方のDO 4. =(-m)-(3m²-m-3) =-2m²+m+3 したがって -2m²+2m+6 =-2(m²-m)+6 2 =-2{(m −1 )² -(+)}+6 「実数解をもつ」は, 0」と「D=0」 -2m²+m+3≧0 2m²-m-3≤0 をまとめた「D≧0」 くして (m+1)(2m-3)≤0 3 これより、 -1≤m≤ 範囲をだすには 判別式!! 考える. 九大 (8) したがって、③の範囲で y=-2m²+2m+6のグラフをかくと 13 最大 -1 2 32 3 m ②より、右の図のようになる. 6 よって、グラフより α' + β2 の最大 固定(日) 値、最小値は, 最小 12 mの範囲に注意 2014 13 最大値 m=1/12 のとき 2 R -11 1013! m 122 Focus 最小値 2 (m=-1のとき) 最大・最小の問題は,変域に注意 #s

未解決 回答数: 1
英語 高校生

英検準1級の要約の添削をお願いします🙏 最後の方がまとまり切らなくて入らなかったので、アドバイス欲しいです!

Copenhagen, the capital city of Denmark, has emerged as a shining example of a city proactively addressing global warming. With a comprehensive and ambitious approach to sustainability, Copenhagen has set a goal to become the world's first carbon-neutral capital by 2025. The city has implemented a range of initiatives, including a robust public transportation system, extensive bike lanes, and a commitment to renewable energy sources. One of Copenhagen's notable achievements is its focus on cycling infrastructure, encouraging residents to choose eco-friendly modes of transportation. The city has invested heavily in creating an extensive network of bike lanes and bike-sharing programs, reducing reliance on carbon-emitting vehicles. Additionally, Copenhagen is committed to transitioning to renewable energy, with wind power playing a significant role in meeting its energy needs. While Copenhagen's efforts are widely praised, challenges remain. Critics argue that achieving carbon neutrality by 2025 is an ambitious target and may involve trade-offs, such as increased taxes and potential economic strain. Additionally, the city faces the complexities of balancing urban development with environmental preservation. Nevertheless, Copenhagen's dedication to tackling global warming serves as an inspiring model for other cities, showcasing the potential benefits of sustainable urban planning and the importance of balancing environmental goals with economic considerations.

回答募集中 回答数: 0
英語 高校生

この3つが分かりません。教えてください🙇‍♀️

wal Rainforest trees are used to make things which we use every day. Rubber, for example, is used to make many things. The fruits of many forest trees ( 7 ) — forest people have eaten them for thousands of years. Today, all over the world, people eat rainforest food plants; for example, coffee, tea, oranges, and rice. Corn, which is an important food for many people of the world, is another rainforest plant. In 1970, a disease destroyed half the corn in the United States of America. Scientists began to look for new species in the rainforests. In 1987, in the Mexican rainforest, they found a new species which is stronger than other species. But we nearly lost this new species, because people were already cutting down that part of the Mexican rainforest. Hollywood, Los Angele movie stud (1) knows how many useful plants are already lost because people have SHOULD destroyed many of the rainforests of the world. Directors, actors, and writ The trees of the rainforests help the Earth's air because their leaves use carbon dioxide and make oxygen, which we need to live. its high point in these year They are also important because they control some of the Earth's weather. Through they give out water vapor which makes heavy clouds. The clouds then move to other parts of the Earth and give rain. The clouds also protect the Earth their large leaves, from the sun. (ウ) 日 moved to like Today, the Earth is slowly getting hotter, and in some places changes in the weather are making life much more difficult. We need to learn more about the Earth's weather while we still have the rainforests. and see the golden

未解決 回答数: 0
1/69