Luyện nói tiếng Anh bằng Shadowing qua video: SET Notations | Mathematics: IGCSE, GCSE & O Level (CIE/CAIE, Edexcel, AQA, OCR)

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Hi everyone!
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Welcome to Plaid Academy.
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I really hope this video helps you out.
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If it does, I'd super appreciate it if you could subscribe to my channel, give this video a like, share it with your friends, and leave a positive comment.
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Your support really keeps me motivated to create more great videos
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for you hey everyone in this video we're going to dive
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into the basics of sets we'll cover what a set is the notations of sets and how to perform set operations
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now if you're studying for your ig cse gcse or o level exams with cambridge international Pearson at Excel,
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AQA, or OCR, this video is made for you.
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It's also essential foundational knowledge for anyone heading into higher -level math.
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I hope you have fun learning and start loving math as much as I do.
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Let's get started.
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A set is a collection of objects, which are called the elements or members of the set.
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These objects can be numbers, animals, fruits, colors, in fact, anything you can imagine.
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A set can be described in two ways, by listing all its members or by giving a rule to describe them.
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In both cases, the list or rule is always enclosed in braces or curly brackets.
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For example, here is a set B shown by listing all its members,
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2, 4, 6, 8, enclosed in braces.
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Alternatively, this same set B can be described by a rule,
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the positive even numbers less than 10, also enclosed in braces.
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Both of these represent the exact same collection of objects.
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Next, let's talk about set notation.
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We're going to cover the symbols for the number of elements in a set, is a member of, the empty set,
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the universal set, subsets, complements, intersections, and unions.
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The number of elements or members in the set B is denoted by this symbol.
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Using our sets from before, the number of elements in set B is 4.
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This symbol means is a member of, or is an element of, and the symbol means is not a member of.
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In the above example, 2 is a member of B,
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but 3 is not a member of Next,
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let's talk about empty sets and universal sets.
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This symbol, or this symbol, is used to represent the empty set, or the null set.
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For example, if the set B equals days of the week starting with P,
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then B is empty set because there are no members in set B.
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Therefore, the number of elements in set B is zero.
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Now, the universal set is denoted by this symbol.
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The universal set contains all the elements being considered in a particular problem.
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For example, if our universal set is days of the week, we would list all members as Monday,
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Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday.
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Next, let's talk about subsets and complements.
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This symbol, or this symbol, means is a subset of.
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If set A is a subset of B, it means that every member of A is also a member of B.
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For example, let's look at set B equals 2, 4, 6.
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The all possible subsets of B are set of 2, set of 4, set of 6,
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set of 2, 4, set of 2, 6, set of 4, 6, and set of 2, 4, 6.
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And don't forget, the empty set is also a subset of B.
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The empty set is always a subset of every set.
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Now, the complement of set A is denoted by this symbol.
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It is the set of all elements in the universal set that are not in A.
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For example, if our universe is days of the week, and set A contains days starting with T, which is Tuesday, Thursday.
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Therefore, the complement of set A is Monday, Wednesday, Friday, Saturday, Sunday.
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Next, let's talk about intersection and union.
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The intersection of sets is denoted by this symbol.
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The intersection of A and B is the set of elements which are in both A and B.
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If set A is the positive integers that less than 10 and set B is 2, 3, 7, 11, 14, 25,
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therefore the intersection of A and B is 2, 3, 7.
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Now, the union of sets is denoted by this symbol.
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The union of A and B is a set of elements which are in A or B or both.
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Using our sets from before, the union of A and B is 1, 2, 4, 5, 6, 7,
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8, 9, 11, 14, 25.
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Next, let's talk about how to perform set operations.
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If the universal set is 1, 2, 3, 4, 5, 6,
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7, 8, 9, 10, we have three sets within it.
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Set A is 1, 3, 5, set B is 3,
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4, 5, and set C is 1, 4, 10.
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Now, let's find the complement of set A.
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The complement of set A is all elements in the universal set that are not in A.
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So we remove the members of set A, which are 1, 3, 5, from the universal set.
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Therefore, the complement of A is 2, 4, 6, 7, 8, 9, 10.
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Next, let's find the union of B and C.
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The union of B and C is the set of elements which are in A or B or both.
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Combining them gives us B union C.
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Therefore, the union of B and C is 1, 3, 4, 5, 10.
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Finally, find the intersection of A and B.
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The intersection of A and B is the set of elements which are in both A and B.
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Looking at our lists, 3 and 5 appear in both.
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Therefore, A intersection B is 3, 5.
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Next, let's look at operations involving three sets.
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Using our sets from before, first find the intersection of A, B, and C.
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This is the set of elements that are in all three sets at the same time.
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If we check our lists, there isn't a single number that appears in A, B, and C.
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Therefore, A intersection B intersection C is the empty sets.
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Now, let's find the number of elements in the complement of B and then intersection with A, then union with C.
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This looks tricky, so let's do it step by step.
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Step 1.
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Find the complement of B.
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The complement of set B is all elements in the universal set that are not in B.
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We remove 3, 4, and 5 from the universal set.
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Therefore, the complement of B is 1, 2, 6, 7, 8, 9, 10.
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Step 2.
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Find the intersection of the complement of B and A.
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The intersection of complement of B and A is the set of elements
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which are in both the complement of B and A.
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We look for elements that are in our new list and in set A.
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The only number in both is 1.
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Therefore, the intersection of the complement of B and A is 1.
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Step 3.
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Find the union of that result with set C.
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The union of our result set and set C is the set of elements which are in 1, or C, or both.
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We take our result set, 1, and combine it with everything in set C, 1, 4, 10.
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Therefore, the complement of B.. intersection A and union C is 1 4 10.
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Step 4.
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Find the number of elements, since the number of elements in the complement of B intersection A and union C is 3.
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Next, let's check your understanding of set notation.
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Using our sets from before, state whether the following statements are true or false.
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First, 5 is a member of B.
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This is true because 5 is an individual element found inside set Second,
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the set of 1, 5 is members of A.
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This is false.
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While 1 and 5 are elements of A, the set of 1, 5 is a subset of A, not a member.
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Third, set A is a subset of C.
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This is false.
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For A to be a subset of C, every element in A must also be in C.
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Since 3 and 5 are in A but not in C, A is not a subset.
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Fourth, 4 -5 is a subset of B.
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This is false.
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The notation is wrong.
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The numbers 4 and 5 are just a list of elements of B.
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To represent a subset, they must be enclosed in braces to create a set, 4 -5.
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Once you add the braces, 4 -5 is a subset of B would be true.
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I really hope this video helps you out.
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If it does, I'd super appreciate it if you could subscribe to my channel, give this video a like, share it with your friends, and leave a positive comment.
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Your support really keeps me motivated to create more great videos for you.

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Từ vựng và ghi chú luyện nói cho bài học này

Video này có 121 câu và 1354 từ để luyện shadowing. Phần lời nói dài 11:55. Người nói giữ tốc độ đều, khoảng 114 từ mỗi phút, vừa sức để nói đuổi theo. Chỉ 79% số từ nằm trong 3.000 từ tiếng Anh thông dụng nhất, nên từ vựng khá khó.

Từ vựng quan trọng trong video

13 từ ít gặp trong video, kèm phiên âm và nghĩa:

  • element /ˈɛləmənt/ (danh từ) — yếu tố. One of the simplest or essential parts or principles of which anything consists, or upon which the constitution or fundamental powers of anything are based.
  • intersection /ˈɪntəɹˌsɛkʃən/ (danh từ) — ngã đường, ngã tư. The junction of two (or more) paths, streets, highways, or other thoroughfares.
  • subset /ˈsʌbˌsɛt/ (danh từ) — tập hợp con, tập con. A set A such that every element of A is also an element of S.
  • symbol /ˈsɪmbəl/ (danh từ) — ký hiệu, biểu tượng. A character or glyph representing an idea, concept or object.
  • mathematics /mæθ(.ə)ˈmæt.ɪks/ (danh từ) — toán học. An abstract representational system studying numbers, shapes, structures, quantitative change and relationships between them.
  • subscribe /səbˈskɹaɪb/ (động từ) — đăng kí. To write (one’s name) at the bottom of a document; to sign (one's name).
  • motivate /ˈmoʊ.tɪ.veɪt/ (động từ) — khích lệ, động viên. To provide someone with an incentive to do something; to encourage; to actuate.
  • dive /daɪv/ (động từ) — lặn. To swim under water.
  • bracket /ˈbɹækɪt/ (danh từ) — dấu ngoặc đơn. A fixture attached to a wall to hold up a shelf.
  • null /nʌl/ (danh từ) — rỗng. A non-existent or empty value or set of values.
  • curly /ˈkɝli/ (tính từ) — xoăn, quăn. Having curls.
  • enclose /ɪnˈkloʊz/ (động từ) — bao vây. To surround with a wall, fence, etc.
  • integer /ˈɪn.tɪ.d͡ʒə(ɹ)/ (danh từ) — số nguyên. A number that is not a fraction; an element of the infinite and numerable set {..., -3, -2, -1, 0, 1, 2, 3, ...}.

Cụm động từ bạn sẽ nghe

  • look for (động từ) — tìm, tìm kiếm. To seek.

Phát âm cần chú ý

Người nói dùng 8 dạng rút gọn, ví dụ I'd, we're, don't. Hãy nói theo dạng ngắn đúng như bạn nghe.

  • Âm “sh” và “zh”: intersection /ˈɪntəɹˌsɛkʃən/, notation /noʊˈteɪʃən/, foundational /faʊnˈdeɪ.ʃə.nəl/
  • Từ dài — đặt trọng âm cho đúng: intersection /ˈɪntəɹˌsɛkʃən/, universal /ˌjunəˈvɜɹs(ə)l/, mathematics /mæθ(.ə)ˈmæt.ɪks/, alternatively /ɔlˈtɝ.nə.tɪv.li/, foundational /faʊnˈdeɪ.ʃə.nəl/

Cách luyện với video này

  1. Nghe hết video một lần, chưa cần nói, và ghi lại những từ bạn chưa biết.
  2. Nói đuổi từng câu ở tốc độ bình thường, lặp lại mỗi câu đến khi nhịp của bạn khớp với người nói.
  3. Ghi âm giọng mình rồi so với bản gốc, chú ý các từ như element, intersection, subset.

Ngữ pháp trong video

Những cấu trúc người nói dùng nhiều nhất, kèm đúng cụm từ trong video:

Cấu trúcTrong video
Câu điều kiện if + mệnh đề, will/would + động từ — điều kiện và kết quảIf it does, I'd super
Câu bị động be + quá khứ phân từ — nhấn vào việc xảy ra, không phải người làmis made · are called · can be described
Mệnh đề quan hệ who / which + mệnh đề — thêm thông tin về người hoặc vậtobjects, which are · elements which are

Phương Pháp Shadowing Là Gì?

Shadowing là kỹ thuật học ngôn ngữ có cơ sở khoa học, ban đầu được phát triển cho chương trình đào tạo phiên dịch viên chuyên nghiệp và được phổ biến rộng rãi bởi nhà đa ngôn ngữ học Dr. Alexander Arguelles. Nguyên lý cốt lõi đơn giản nhưng cực kỳ hiệu quả: bạn nghe tiếng Anh của người bản xứ và lặp lại to ngay lập tức — như một "cái bóng" (shadow) đuổi theo người nói với độ trễ chỉ 1–2 giây. Khác với luyện ngữ pháp hay học từ vựng bị động, Shadowing buộc não bộ và cơ miệng phải đồng thời xử lý và tái tạo ngôn ngữ thực tế. Các nghiên cứu khoa học xác nhận phương pháp này cải thiện đáng kể phát âm, ngữ điệu, nhịp điệu, nối âm, kỹ năng nghe và độ lưu loát khi nói — đặc biệt hiệu quả cho người luyện IELTS Speaking và muốn giao tiếp tiếng Anh tự nhiên như người bản ngữ.

Phương pháp shadowing: đọc hướng dẫn từng bước đầy đủ →