Sign of Trig Functions

Duration: 9 min

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Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. Section A: General Awareness: Polity, वैज्ञानिक उपलब्धियाँ और अनुसंधान / Scientific Achievements and Research, Biology, Chemistry, Static General Knowledge, History, Geography, Indian Economy, समसामयिकी / Current Affairs, Evolution of Indian Banking (Banking & Financial Awareness), Environment
  3. Section A: General Intelligence & Reasoning ability: श्रेणी / Series, कूट लेखन एवं कूट वाचन / Coding-Decoding, Data Sufficiency, अशाब्दिक तर्क / Non-Verbal Reasoning, Analytical Reasoning (Counting Figures Reasoning), रक्त संबंध / Blood Relations, Syllogisms, कथन आधारित तार्किक विवेचन / Statement-Based Reasoning, बैठक व्यवस्था एवं पहेलियाँ / Seating Arrangement and Puzzles, दिशा एवं दूरी / Direction and Distance, गणितीय संक्रियाएँ एवं लुप्त संख्या / Mathematical Operations and Missing Numbers, कैलेंडर एवं घड़ी / Calendar and Clock, Clock, घन, पासा एवं आकृतियों की गिनती / Cubes, Dice and Figure Counting, आँकड़ों की पर्याप्तता एवं निर्णय क्षमता / Data Sufficiency and Decision Making, वर्णमाला एवं संख्या परीक्षण / Alphabet and Number Test, Crypt Arithmetic, वेन आरेख, न्याय वाक्य एवं असमानता / Venn Diagrams, Syllogism and Inequalities, Data Arrangement, Inequality, सादृश्यता एवं वर्गीकरण / Analogy and Classification, क्रम एवं रैंकिंग / Order and Ranking, TCS NQT Advanced Reasoning Ability
  4. Section A: Arithmetical & Numerical Ability: अनुपात और समानुपात / Ratio and Proportion, Divisibility Rules, आँकड़ा निर्वचन / Data Interpretation, मिश्रण और एलिगेशन / Mixture and Alligation, Permutation and Combination, Logarithm, संख्या पद्धति / Number System, महत्तम समापवर्तक और लघुत्तम समापवर्त्य / HCF and LCM, Sequence and Series (Series), समय, चाल और दूरी / Time, Speed and Distance, प्रतिशत / Percentage, औसत / Average, लाभ, हानि और बट्टा / Profit, Loss and Discount, साधारण और चक्रवृद्धि ब्याज / Simple and Compound Interest, समय और कार्य / Time and Work, Pipe and Cistern, घन क्षेत्रमिति / Solid Mensuration, सरलीकरण, घातांक और करणी / Simplification, Indices and Surds, Algebra, Probability, Mental Ability, Age Problems, Partnership, Statistics, Arithmetic, Speed Mathematics and Basic Mathematics, Miscellaneous
  5. Section A: English Language & Comprehension: Vocabulary, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Verbs and Tenses, Reading Comprehension, Parts of Speech, Sentence Construction, Prepositions and Conjunctions, Direct and Indirect Speech, Sentence Completion (Fill in the blanks), Sentence Structure and Common Errors, Modals, Transformation of Sentences, Sentence Correction (Error Correction), Adverb, Conjunction, Cloze Test (Cloze Passage)
  6. Section A: Hindi Language & Comprehension: भाषा, लिपि और वर्ण, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, पद-भेद और रूप-विकार, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, संधि, समास, विलोम शब्द, पर्यायवाची शब्द, सामान्य अशुद्धियाँ, अनेक शब्दों के लिए एक शब्द, शब्द-भंडार, अपठित बोध, Multi-Topic Content (Cross-Concept Material), वर्णमाला
  7. Section B: Programming, Data Structures, OOP & Java: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Java, OOPS with C++, Language Design, Intro to Compilers, Visual Basics, Syntax Analysis: Bottom-Up, Object Oriented Technology
  8. Section B: Computer Networks, TCP/IP & Network Security: Introduction to CN, Data Communication, DLL: Flow Control, DLL: Access Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Access Technologies, Network Security, Society, Law & Ethics, Mobile Computing, Net Layer:Routing Protocol, Cyber Safety and Security
  9. Section B: Teaching Methodology: वृद्धि और विकास / Growth and Development, Concept of Pedagogy, विकास के सिद्धांत / Theories of Development, समावेशी शिक्षा / Inclusive Education, Experiential Pedagogy, आकलन और मूल्यांकन / Assessment and Evaluation, समाजीकरण और जेंडर / Socialisation and Gender, National Education Policy (NEP) 2020, संज्ञानात्मक प्रक्रियाएँ / Cognitive Processes, शिक्षण योजना और शिक्षण कौशल / Teaching Planning and Teaching Skills, Personality Development, शिक्षण विधियाँ / Teaching Methods, अधिगम और व्यवहारवादी सिद्धांत / Learning and Behavioural Theories, Learners & Learning Process, Factors Affecting Teaching, शिक्षण विधियाँ एवं उपागम / Teaching Methods and Approaches, शिक्षण-अधिगम प्रक्रिया एवं कक्षा प्रबंधन / Teaching-Learning Process and Classroom Management, शिक्षण सहायक सामग्री एवं शैक्षिक तकनीकी / Teaching Aids and Educational Technology, सूक्ष्म शिक्षण एवं कक्षा संप्रेषण / Microteaching and Classroom Communication, आकलन एवं मूल्यांकन / Assessment and Evaluation, पाठ्यचर्या, कला एवं सह-शैक्षिक क्षेत्र / Curriculum, Arts and Co-curricular Areas, दिव्यांग बच्चों की शिक्षा / Education of Children with Disabilities, शिक्षक: गुण, व्यावसायिक नैतिकता एवं विकास / Teacher: Qualities, Professional Ethics and Development
  10. Section B: Digital Electronics / Boolean Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Analog-Digital Conversion
  11. Section B: Operating Systems & Linux: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, File Management, Disc Scheduling, Unix OS, Linux OS, Distributed Systems, Windows OS
  12. Section B: Data Base Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, File Organization & Indexing, Transaction Management, Concurrency Control, Database Security & Authorization, Database Recovery, Data Warehousing & Mining
  13. Section B: Internet & Web Technologies: Website, Browser & Services, Internet Fundamentals, Web Design & Development, Protocols & Services, Web Publishing & Hosting, Server Side & Security, HTML Basics, CSS, Emerging Technologies, JavaScript-Basics, .Net Programming, Electronic Data Interchange and E-Commerce, XML
  14. Section B: Computer Fundamentals, IT Basics & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design, Programming the Basic Computer, Terms & Abbreviations, MS Office Applications, Instr Formats & Modes, Floating Point Rep, कंप्यूटर के मूल सिद्धांत / Computer Fundamentals, साइबर सुरक्षा / Cyber Safety and Security, कंप्यूटर सॉफ़्टवेयर / Computer Software, ऑपरेटिंग सिस्टम / Operating System, वर्ड प्रोसेसिंग (MS Word) / Word Processing (MS Word), कंप्यूटर नेटवर्क / Computer Networks, प्रेज़ेंटेशन (MS PowerPoint) / Presentation Software (MS PowerPoint)
  15. Section B: Python Language: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  16. Section B: Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, extras, Fundamentals of Systems and Information Systems
  17. Section B: Design & Analysis of Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  18. Section B: Mathematics: Linear Algebra, Calculus, Trigonometry, Vectors, Set Theory, Functions, Relations, Propositional and Predicate Logic, Research Process Steps, Graph Theory, समुच्चय, संबंध, फलन और विविक्त गणित / Sets, Relations, Functions and Discrete Mathematics, संख्या पद्धति और संख्या सिद्धांत / Number Systems and Number Theory, यूक्लिडीय ज्यामिति और क्षेत्रमिति / Euclidean Geometry and Mensuration, सांख्यिकी और प्रायिकता / Statistics and Probability, निर्देशांक ज्यामिति, सदिश और त्रिविमीय ज्यामिति / Coordinate Geometry, Vectors and 3D Geometry, बहुपद, समीकरण और सम्मिश्र संख्याएँ / Polynomials, Equations and Complex Numbers, समतल क्षेत्रमिति / Plane Mensuration, प्रतिचयन / Sampling
  19. Section B: Computer Graphics, Multimedia & Mobile Computing: Basics of Computer Graphics, 2-D Geometrical Transforms and Viewing, 3-D Object Representation, Geometric Transformations and Viewing, Multimedia
  20. Section B: Emerging Trends: Emerging Tech Trends, Knowledge Representation, Natural Language Processing, व्यापार, विपणन एवं उपभोक्ता संरक्षण / Trade, Marketing and Consumer Protection
  21. DSSSB Previous Year Paper:
  22. Business Studies and Management: Business Communication, प्रबंध के सिद्धांत एवं कार्य / Principles and Functions of Management, लेखांकन के आधार एवं लेन-देनों का अभिलेखन / Accounting Fundamentals and Recording of Transactions, Business Economics, ह्रास, अंतिम खाते व कंप्यूटरीकृत लेखांकन / Depreciation, Final Accounts and Computerised Accounting, Knowledge Management & New Economy
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a comprehensive lesson on the signs of trigonometric functions in the four quadrants of the coordinate plane. The instructor begins by setting up a standard Cartesian coordinate system, labeling the x and y axes, and then proceeds to define the quadrants. Key angles, including 0, π/2, π, 3π/2, and 2π, are marked on the axes to establish the boundaries of the quadrants. The core of the lesson is the explanation of the ASTC rule (All Students Take Calculus), which is a mnemonic to remember the signs of the trigonometric functions in each quadrant: All (sine, cosine, tangent) are positive in the first quadrant; Sine is positive in the second; Tangent is positive in the third; and Cosine is positive in the fourth. The video also includes a brief demonstration of the unit circle to explain the definitions of sine and cosine as the y and x coordinates of a point on the circle, respectively. Finally, the video presents a table of standard trigonometric values for angles 0°, 30°, 45°, 60°, and 90°, showing the values for sine, cosine, tangent, cotangent, secant, and cosecant, including cases where the function is undefined (N.D.).

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with the title 'Sign of Trigonometric functions' written in blue on a black background. The instructor draws a standard Cartesian coordinate system, labeling the horizontal axis as 'x' and the vertical axis as 'y'. He then marks the origin as 'O' and proceeds to label the key angles on the axes: π/2 at the top of the y-axis, π on the negative x-axis, 3π/2 at the bottom of the y-axis, and 2π on the positive x-axis. The instructor explains that these angles divide the plane into four quadrants, which are numbered I, II, III, and IV in an anti-clockwise direction, starting from the positive x-axis.

  2. 2:00 – 5:00 02:00-05:00

    The instructor labels the four quadrants as 'Ist Qua.', 'IInd Qua.', 'IIIrd Qua.', and 'IVth Qua.' in their respective positions. He then introduces the concept of 'Quadrantal Angles' and lists them as 0, π/2, π, 3π/2, and 2π. The main focus shifts to the signs of the trigonometric functions. The instructor writes the mnemonic 'ASTC' in a red box. He explains that in the first quadrant, all trigonometric functions (sin, cos, tan, cot, sec, cosec) are positive. In the second quadrant, only sine (sin) is positive. In the third quadrant, only tangent (tan) is positive. In the fourth quadrant, only cosine (cos) is positive. He uses the mnemonic 'All Students Take Calculus' to help remember this, with the first letter of each word corresponding to the functions that are positive in each quadrant.

  3. 5:00 – 8:49 05:00-08:49

    The instructor continues to elaborate on the signs of the trigonometric functions in each quadrant, writing 'sin +ve', 'cos +ve', 'tan +ve', 'cot +ve', 'sec +ve', and 'cosec +ve' in the first quadrant, and then 'sin +ve', 'cos -ve', 'tan -ve', 'cot -ve', 'sec -ve', 'cosec +ve' in the second quadrant, and so on for the other quadrants. He then draws a unit circle to explain the definitions of sine and cosine. He shows a point P on the circle with coordinates (cosθ, sinθ) and explains that sinθ = y/r and cosθ = x/r, where r is the radius. The video then transitions to a table titled 'Values at angles' which lists the values of sinθ, cosθ, tanθ, cotθ, secθ, and cosecθ for angles 0°, 30°, 45°, 60°, and 90°. The table shows that for 90°, tanθ and secθ are undefined (N.D.), and for 0°, cotθ and cosecθ are undefined (N.D.).

The video systematically teaches the sign conventions of trigonometric functions across the four quadrants of the coordinate plane. It begins with the foundational setup of the coordinate system and the definition of quadrants. The core of the lesson is the ASTC mnemonic, which provides a clear and memorable rule for determining the sign of any trigonometric function based on the quadrant in which the angle lies. The lesson is reinforced with a visual aid of the unit circle, which grounds the abstract concept in a geometric definition. The video concludes with a practical table of standard trigonometric values, which is essential for solving problems and understanding the behavior of these functions at key angles.

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