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?y2?2x上点(1,2)到点A(2,0)的距离最短。
⒌圆柱体上底的中心到下底的边沿的距离为L,问当底半径与高分别为多少时,圆柱体的体积最大?
设园柱体半径为R,高为h,则体积
V??R2h??(L2?h2)h
令:V???[h(?2h)?L2?h2]??[L2?3h2]?0?L?3hh?3L3R?2L3?当h?3,R?32L时其体积最大。3
⒍一体积为V的圆柱体,问底半径与高各为多少时表面积最小? 设园柱体半径为R,高为h,则体积
V??R2hS表面积?2?Rh?2?R2?2?V?2?R2R
令:S???2VR?2?4?R?0VV?R3?R?32?2?
h?34V?
R?3V4Vh?32? ?时表面积最大。
答:当
⒎欲做一个底为正方形,容积为62.5立方米的长方体开口容器,怎样做法用料最省?
62.5?x2h解:设底连长为x,高为h。则:
?h?62.5x2
S?x2?4xh?x2?侧面积为:
250x
答:当底连长为5米,高为2.5米时用料最省。
S??2x?令
250?02x?x3?125?x?5(四)证明题
⒈当x?0时,证明不等式x?ln(1?x).
ln(1?x)ln(1?x)?ln11???1x(1?x)?11??证:由中值定理得:
(???0)
ln(1?x)?1?x?ln(1?x)xx⒉当x?0时,证明不等式e?x?1. ?设f(x)?ex?(x?1) f?(x)?ex?1?0(当x?0时)?f(x)?0,即ex?(x?1)证毕
(当x?0时)
?当x?0时f(x)单调上升且f(0)?0
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请您务必删除一下内容,O(∩_∩)O万分谢谢!!!2015年中央电大期末复习考试小抄大全,电大期末考试必备小抄,电大考试必过小抄 Indonesia has emerged as a top vacation destination for Chinese this summer, along with Thailand's Phuket island and the Maldives archipelago. Encouraged by growth in Chinese travelers to Indonesia, the government in Jakarta has recently relaxed its visa policy. Since June 10, Chinese tourists can enter Indonesia through nine appointed locations, including the Soekarno Hatta International Airport in Jakarta, the Ngurah Rai International Airport in Bali and the Kuala Namu International Airport in Medan, by just getting their passports stamped on arrival. Officially, it is called the \tourists can save $35 on visa fees, which will likely make trips to Indonesia more alluring. While such an arrangement allows Chinese visitors to stay up to 30 days for the purpose of traveling, those seeking extensions will need to get paid visas from that country's missions inBeijing, Shanghai, Guangzhou or Hong Kong, according to an official at the Indonesia embassy in Beijing. Santo Darmosumarto, head of the embassy's information, social and cultural section, says the new policy is aimed at strengthening people-to-people contacts between the two countries. Dai Yu, marketing director of Ctrip, a major Chinese online travel agency, says: \since the policy was announced.\Indonesian President Joko Widodo proposed that his country and China aim to increase two-way visits to a maximum of 10 million people in the next few years. The Indonesian government has set their sights on greeting 2 million Chinese tourists by the end of this year, according to the official. \Indonesian nationals would also be given preferential treatment while visiting China,\says Darmosumarto. In 2013, the number of Chinese tourists who visited Indonesia stood around 807,000. Last year, it increased to 959,000, he adds. Bali remains the most popular site among Chinese tourists. In February, more than 92,200 Chinese tourists made trips to Bali, ranking first among overseas visitors, the Bali Times reported. Last year, the island witnessed more than 586,000 arrivals from China, an increase of 51 percent over 2013. \just for sightseeing, but also for weddings, honeymoons, golf and many outdoor activities,\Garuda, Indonesia's national airliner. Garuda offers three nonstop flights between Beijing and Bali, and four each week between Beijing and Jakarta. There are daily flights from Guangzhou, in Guangdong province, and Shanghai to Jakarta as well. It takes from six to eight hours on a nonstop flight to reach Indonesia from China. Indonesia is home to more than 17,000 islands. Tourists can tour Yogyakarta to see Prambanam and Borobudur, two historical and religious sites, and explore the local handicraft markets. The base of a volcano, Bandung, which is also known as the \adventure-seekers. Many ecotourism destinations, such as Toba Lake in Sumatra, Tanjung Puting National Park in Kalimantan and Bunaken in Manado, are places the embassy official recommends for tourists. Indonesia boasts world-class surfing facilities along the shores of Sumatra down to Nusa Tenggara Islands. Recently, Lombok, a sister island east of Bali has gotten so much attention from Chinese travelers that some travel agencies are offering twin packages for Bali and Lombok. The best time to visit Bali is from May to October, when it doesn't rain much and the weather is cool. At press time, a weeklong package from Shanghai or Guangzhou to Bali was a little more than 3,000 yuan ($480) on Ctrip's website. Chinese tourists have taken a shine to rafting in Ubud, sightseeing in Tanah Lot, and surfing and diving in Nusa Lembongan, says Dai. Civet coffee, essential oil and woodcarvings are among the most popular products for Chinese tourists in Indonesia, she says. Indonesian food is also something that visitors shouldn't miss. Local cuisines feature many spices, including peppers and cloves, and coconut pulp. Fried rice, \pig are recommended. Children's illustration books first appeared in the 1600s in Europe. Their passage to China, however, took much longer, roughly 300 years. In China, children's illustration books have a history of just 100 years and their development can be divided into four stages. From early 1900s to mid 1900s, a large number of books and magazines with illustrations appeared with the fast development of the modern publishing industry. The illustration arts at that time were a mixed genre of Chinese traditional paintings and the western style, and most of the stories originate from the fundamental changes that China experienced after the collapse of Qing Dynasty (1644-1911), the warlord struggles and the war against the Japanese invasion. The second stage was from mid 1900s to late 1970s, when the \revolution\publishing houses for children gave birth to a large number of illustration-story books, which made a good use of folk art techniques, such as wood board carving, frescoes, and ink and wash painting, etc. Many of the popular stories are from Chinese history and wars after 1900s. The third stage is from early 1980s to late 1990s, a golden period for the development of children's illustration books. The reform and opening-up brought in new concepts and ideas from the West to China, a country that had been closed to the West for nearly three decades. Fast development of economy, society and culture provided the writers and painters with a lot of inspiration to create new literature works and draw illustrations. China also imported large amounts of children's illustration books from the West and Japan. Many young parents in China have a strong nostalgia about children's illustration books they read in the 1980s and 1990s. This is also the last era in China's artistic innovation before the advent of the Internet period. The fourth stage is featured with the spread of the Internet and the other computerized means of art innovation. The hand-drawn children's illustration books are gradually replaced by cartoons drawn and copied by software and machines, and shown on tablets, computers, television and smart phones, instead of books. Hainan Tropical Wildlife Park and Botanical Garden is nature's haven, with no less than 4,000 rare birds and animals representing 200 species. With tropical forest covering over 90 percent of its area, the garden offers beautiful views of a wide range of tropical plants, flowers and fruit trees. The scenic spot about 25 kilometers from the center of Haikou offers a drive-thru safari tour where you can get up close with elephants, lions and bears. The \Foot\m for a small fee. Visitors also can see what happens when you breed a lion and a tiger. Two unique attractions are rare hybrids: a liger, the offspring of a mallion and a female tiger and a tigon, which is created by a female lion and a male tiger. As a teaching center of -可编辑修改-
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the National Popular Science Education program, the park also serves as a second classroom for students to learn about wildlife and plants. Since it was established in 1995, it has received more than one million student visitors. At a crucial moment when pessimism has brought the Greek crisis to such a head that the country is closer to a default on its debt repayments than ever, Li offered a spark of enthusiasm to restart the stalled talks by calling on Greece and its creditors to reach a last-minute deal that will allow Greece to remain in the eurozone. Given the escalation of the country's crisis over the weekend sent a shock wave through the global stock markets on Monday, there are ample reasons to worry about the uncertainties surrounding the events in Greece and the effect a default would have on Europe, relations between China and the EU, global financial stability and the nascent global economic recovery. Greece has announced that it will hold a referendum on a bailout plan proposed last week by the country's creditors. In response, Greece's eurozone partners have refused to extend the country's bailout program and the European Central Bank capped its emergency support for the country's banks. A real danger now looms of Greece exiting the euro, which might derail the global economic recovery and damage the long-term viability of the euro as a currency. However, such a tragedy is neither certain nor unavoidable. The EU should shoulder its responsibility to prevent the Greek crisis from overshadowing the fragile global recovery. As a major customer and supplier of the 28-nation EU, and a responsible long-term holder of Eurobonds, China's confidence in and commitment to a strong eurozone offers EU leaders the necessary support to look at the Greek crisis from a broader and longer perspective. When Li said that China will not only consider a China-EU investment platform to back European Commission President Jean-Claude Juncker's plan to revive the European economy, but also buy more bonds issued by the European Investment Bank, EU leaders should be clear that China wants to see the EU maintain its integrity and a forward trajectory. Such a confidence-building effort is particularly valuable, especially from such a large country as China which already has a huge stake and seeks to further expand it in a strong eurozone. It will be a tragedy to allow inaction over the Greek crisis to stand in the way of growth-boosting Sino-EU cooperation. Like a shining pearl, West Lake is the symbol of Hangzhou city. From ancient times, many poems have praised the amazing scenery of the lake. At the very beginning, the West Lake was a part of the Qiantang River. In the year 822, Bai Juyi, a famous poet and an officer of the Tang Dynasty (AD 618-907), suggested to build a stronger causeway to store water so that the lake was doubled in size. And during the Song Dynasty (AD 960-1279), many temples and pagodas were built due to a Buddhist revival, and the look of West Lake was formed at that time. The West Lake is quite big and features different classic views from different locations. Technically, there are ten scenes which were marked by Emperor Qianlong with four-character inscriptions 200 years ago, such as the Melting Snow on the Broken Bridge and Sunset Glow over Leifeng Pagoda.
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2020年电大《高等数学基础》期末模拟考试试题及参考答案资料必考重点
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