In the real number range, the square of any number is non-negative, so in the real number range, the square of any number can't be negative.
In order to realize the idea that negative numbers can also be squared, people created imaginary unit I, which stipulated I178; =- 1
This ai(a is a real number other than 0) is called pure imaginary number, and the square of these pure imaginary numbers is (AI)178; = a 178； I 178； =-(a 178； )
Because a is a real number other than 0, a178; Is a positive number, then-(a178; ) is negative.
These numbers are studied in the field of complex numbers.
How do you feel after reading the text Dream of Green Leaves? Your childhood must be a wonderful dream. On the way to school, my daughter suddenly stopped and squatted down to pick up two poplar leaves from the ground. She quickly wiped the leaves gently, leaving only two bare petioles, and then gave me one of them: "Mom, let's play!" " I smiled with relief and took the initiative to put the petiole through my daughter's root and bent it. The daughter shouted, "One, two!" "With a gentle force, my daughter stumbled back and her petiole broke in two." Mom, compare it again! ""My daughter decisively threw away the broken handle and bent down to pick up the fallen leaves.
Seeing my daughter skipping down to pick up the fallen leaves, my mood can't help warming up. I used to play this game repeatedly with my friends, this game with petioles as props. I can't help looking down and picking up a leaf. Watching, those memories of green leaves flashed before my eyes.
I was born in the countryside, and my childhood was inseparable from nature. There is a forest in my hometown, which is not big, but it is our paradise. In summer, every time after school, we go to hide cats and dogs in the Woods. Naughty boys always climb tall willows, break them and put them on their heads. When playing war games, they used their wicker rings to grab the title of early commander. The slender willow leaves dance with the wind, full of amorous feelings and pride. We little girls can only envy and worship.
We can't climb trees, but we can go downstream. There is a lotus pond not far from the Woods. We took off our shoes and socks, rolled up our trouser legs, waded carefully, stretched out our arms, broke off the lotus leaves, and the cheerful laughter stunned the dragonfly standing in the lotus. Hold the round lotus leaf high. If it rains, the lotus leaf is a small umbrella to keep out the rain. Lotus leaves are tired, so I immediately put the roots up, and the long braids stand up. The cool lotus leaf sticks to the head, as if it were cool and straight into the heart, so refreshing and particularly comfortable.
Not far away, there was a clear voice. I don't know which clever friend is playing beautiful music with green leaves. I saw him pick a leaf of Sophora japonica and gently put it in his mouth, and beautiful music came out. We are greedy and unconvinced. We have torn off the leaves of Sophora japonica. Except for the occasional deep "beep" sound, there is no more beautiful music, so we blow harder and our cheeks turn blue with pain, or those "beep" sounds. We threw leaves, grabbed a handful of Sophora japonica leaves, and suddenly sprinkled them on his head and mouth when no one was looking. Then I ran away like I ran away, and there was another burst of cheerful laughter.
In autumn, we ran all over the Woods and fields, looking for complete and beautiful leaves everywhere. The teacher said that whoever collected the most complete leaves and made the most exquisite specimens was elected as the monitor. What a great temptation for us young people who are good at acting! We pricked our hands and broke our calves to pick leaves, but we didn't care at all. We collected more than half a basket and sat on the grass to pick it up. We are so serious and careful, just like playing with a weak life. After selection, we put our favorite leaves in a thick book and air-dry them to make specimens. Those who are not selected will not be thrown away easily. We take them home, wear them with long lines and take them to school to decorate our classroom. For a time, the green of nature was locked into our classroom so easily.
In winter, the cold wind blows off yellow leaves. We came to the Woods again with bags and rakes. First, I made some beautiful rolls on the carpet paved with leaves, made some monkey fists, and talked and laughed. Then we began to collect fallen leaves with our own tools, and no one was idle. After installation, everyone will pick up some leaves that look like flexible petioles, remove dead leaves and collect a petiole to compare whose petiole is tougher and judge best. After the game, everyone has almost rested, and then everyone will go home with a bag full of leaves, which will definitely be praised by their mothers. They smiled and squinted, or gave us an egg or a few cents. Our faces must be very satisfied and happy.
"Mom, what are you thinking?" My daughter stood in front of me with a rolled petiole in her hand. "Mom had a dream about green leaves!" "I smiled softly, yes! A dream of green leaves, a beautiful childhood memory, there are countless joys and laughter in this dream, is there your shadow in this dream?
How do you feel after reading Dream of Green Leaves? 1. The leaves of peach trees have diuretic effect; Ginkgo garden can astringe lung, relieve asthma, promote blood circulation, remove blood stasis and relieve pain. Used for cough and asthma due to lung deficiency; Coronary heart disease, angina pectoris, hyperlipidemia, anticoagulation, there is a certain probability to improve memory. It can also promote blood circulation and prevent cardiovascular diseases.
The whole article shows us the carefree childhood of children and the magic of nature.
How do you feel after reading the article "A Letter from an Unknown Grandpa"? You should keep your promise. Sometimes people will take a casual remark seriously, but you have forgotten it for a long time, so you can't easily promise.
The readers of this article want to walk into nature with the author of this picture and feel the wonderful sound. Will you find anything new? You will find that nature is beautiful, and you will involuntarily have a good desire to love nature.
How do you feel after reading the article "Clock in Nature"? The biological clock in this paper refers to the cock crowing. Its function is to tell the time.
Because there is a cock crowing in the article.
This paper adopts the explanation method of cause and effect.
How do you feel after reading the article "Candles for Grade Eight"? How does it feel to cross national boundaries? Deep and strong maternal love, as well as the cruelty of the enemy and the unremitting spirit of the Red Army.
How do you feel after reading the article "A Gift of Five Dollars"? During the summer vacation, my father asked me to preview the sixth grade books. I was just browsing. When I turned to the article "A gift for five dollars", many question marks popped up in my mind: What gift? Who is this gift for? ..... With these questions, I finished reading this article with relish.
The author tells the touching story that the protagonist Ruben found a linen bag in a poor and embarrassed environment and gave it to his mother only on Mother's Day in exchange for a gift of five yuan. Nearly a year has passed, and Reuben has been carrying out his sacred mission. Finally, he bought a gift for his mother and left her with tears of happiness.
Reuben's filial piety left a lingering impression on me. His spirit moved me, and his filial piety made me feel ashamed. Lu's instinct to do such touching things stems from his mother's love for Reuben. Yes, which mother in the world doesn't love her children? Mother's love for her children reminds me of a poem: I love my son endlessly and I am happy to go home. Cold clothes are needle and thread, and letters from home are ink stains. If you encounter pity, you will ask for it. I am ashamed of the son of man and dare not sigh. This is a poem written by a soldier praising maternal love. This poem represents the mother's love for Reuben and every mother's love for her children. Mothers in the world love their children, but not many love their mothers. Even fewer people like Reuben love their mother. So, don't let the world revolve around maternal love. We should also work hard to release some love for our mothers and make the world full of love and care for our parents.
Friends, be kind to your parents! They paid a heavy price for you. No matter when and where, you must understand that there are only two people standing by your side forever: father and mother.
What is your biggest feeling after reading the article "Joining the Team Ceremony"? Looking forward to, looking forward to, finally looking forward to10123 October-China Young Pioneers Team Building Day. That afternoon, we watched the grand and warm entrance ceremony for freshmen with great interest. When the music of "Chinese Young Pioneers Team Song" started, I couldn't help but get lost in thought when I looked at the bright smiling faces and bright red scarves on my chest ... At the age of 8, I stepped into the school gate with my small schoolbag on my back for the first time and looked around curiously. Hey, why are those big brothers and sisters wearing a red tie on their chests? That red tie fluttered in the wind. Bright and beautiful. Why do big brothers and sisters have this red tie? This red tie is really beautiful. If only I had one! So I went to ask the teacher, and the teacher said, "This is not a tie, but a red scarf. It is the symbol of Chinese Young Pioneers. As long as you behave well and study hard, you can become a young pioneer, and then you can wear a red scarf. " Well, I can also wear a red scarf. I will study hard, make progress every day, and strive to become a young pioneer as soon as possible, and wear this bright red scarf!
After reading the article "The History of Taiwan Province Province's Occupation is Over", we can see that China's comprehensive strength has increased, and it is no longer oppressed by foreign powers, and it will be beaten if it falls behind. We must work hard to build the motherland's tomorrow.