已知命题p:4x-3≤1且x≥1/2；命题q：x²-(2a+1)x+a(a+1)≤0.若p是q的充分不必要条件,求实数a的取值范围.这题前面我都懂.p：1/2≤x≤1.q:a≤x≤a+1.p真包含于q.我有一点不明白那不应该是a＜1/2且a+1＞

已知命题p:4x-3≤1且x≥1/2；命题q：x²-(2a+1)x+a(a+1)≤0.若p是q的充分不必要条件,求实数a的取值范围.
这题前面我都懂.p：1/2≤x≤1.q:a≤x≤a+1.p真包含于q.
我有一点不明白那不应该是a＜1/2且a+1＞1吗?为什么是a≤1/2且a+1≥1呢?这个等号为什么能取到呢?不是真包含吗?

我能明白您的意思,不取等号你很明白 对吧,就是取了等号很难明白 可是a≤1/2且a+1≥1就是对的吗,明显是不能取到等号的,若取了那就是充分必要条件,数学是很严谨的,有了这一个不符合就不对,跟题目意思不符,就是说你认为对的答案是不正确的,就不应该去等于号,你可以再去问问你们的老师,我认为不能取等号 只要您的学习疑惑解决了就是好的 时隔2日再回答这个问题.可以很正确的回答你的问题了,可以取到的,当a=0 或 当a=1/2时（也就是取等于号时）你带进去看看什么情况,怎么样,是符合的吧,,你的问题解决啦

我晕 我才刚上初中 看的我晕头转向

What is the best gift for your family when you travel to China

Travel, is a good way to relieves stress and raises energy, was widely admitted by the people today. With the sustainable and f...

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What is the best gift for your family when you travel to China

Travel, is a good way to relieves stress and raises energy, was widely admitted by the people today. With the sustainable and fast development of Chinese economy, China has become more attractive to the foreign people. China Tours are more popular than before.
Many of us prefer to buy some gifts to our family so that they can getsome idea of the different culture of the different country. As we all know, China is a historical country, there are many amazing scene of natural, and disparate custom that we have never seen in Western countries. So for example, if we Travel to Beijing, what gift is the best for our Family?
1. Chinese Painting Mask
Beijing Opera is the quintessence of Chinese culture. And people come to Beijing often have a try to the Beijing Opera. Many of them like the Chinese painting mask because its very special if you have never seen it. Every painting mask represents a person in the history. Chinese people always say that you can see the characteristic of the role from painting mask. In my opinion, its full of the rich Chinese culture.a set of painting masks is also have the collection value.
2. Calligraphy or Chinese Painting
In the ancient China, people use brush and China ink to write and paint. The roots of Chinese painting can be traced back to paintings on Neolithic pottery six or seven thousand years ago. Since similar tools and lines were used for the earliest painting and writing, painting is said to have the same origin as calligraphy. Thus, Chinese paintings usually integrate poetry or calligraphy with themes that include figures, landscapes, flowers, birds and other animals. Traditional Chinese painting remains a highly valued genre, often on exhibit in China as well as other countries. One of my friends said that: Its not colorful but you can get the meaning from the painting only with white and black. It has a magical power to take you to another world.
3. Paper-cuts
This is my favorite. Paper-cuts is a kind of Chinese traditional arts.Chinese Paper Cuts also called Scissor-cut, it is a kind of folk artwork with rich local flavor popularizing in numerous people. Chinese-Paper-cuts were come out during the period of North and South Dynasty. Colorful paper cut by scissors is often used as decoration and forms various artistic styles because of different purposes, such as for window decoration, basket decoration, present decoration and designs. I often wondered that how the paper-cuts were made, it looks very difficult to make the paper to that shape.
4. Embroidery
According to my friends opinion, Chinese embroidery took the fancy of the visitors.Embroidery is the art or handicraft of decorating fabric or other materials with needle and thread or yarn.The embroidery is very beautiful, animated. Its a good suggestion to decorate the wall by embroideries. In China, Su Embroidery, Xiang Embroidery, Yue Embroidery, Shu Embroidery is the most famous. Each kind of embroidery has its own style.
So, thats it. Have you know more about the Chinese gift? Certainly there are many other interesting things in China. These four is the gifts that I think lots of people will be interested in. Hoping that can give you some help in your China Tour. And by the way, Have a nice trip in China!
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What is the best gift for your family when you travel to Chi

What is the best gift for your family when you tra

What is the best gift for your family when you travel to China

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前面你理解的都正确，可这怎么理解不了了！
p真包含于q，也就是q包含p，换句话说p就在q的里面，你画个数轴就知道了，做数学题要注意画图理解。