Graphs, Domain and Range of Trig Func

Duration: 34 min

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Module outline

  1. Aptitude: Ratio and Proportion (Ratios), Divisibility Rules, Data Interpretation, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Percentage, Average, Powers and Exponents (Surds and Indices), Algebra, Probability, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Pipe and Cistern, TCS NQT Advanced Quantitative Ability, Speed Mathematics and Basic Mathematics, Arithmetic, Statistics, Partnership, Age Problems, Mental Ability, Mensuration and Geometry, Linear Algebra, Calculus, Trigonometry, Vectors, Gamified / Game Based Aptitude
  2. Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Syllogisms, TCS NQT Advanced Reasoning Ability, Ranking, Order and Sequence, Analogy, Inequality, Data Arrangement, Venn Diagram, Logical Sequence Of Words, Selection Decision Table (Decision Making), Cubes & Dices, Clock, Calendar, Puzzle Solving (Puzzles), Analytical Reasoning (Counting Figures Reasoning), Directions (Direction Test), Blood Relations, Seating Arrangements
  3. Verbal Ability (English): Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Pronoun, Preposition, Articles, Direct and Indirect Speech, Conjunction, Modals, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Sentence Construction, Active Passive Voice (Voice), Determiner, Facts, Inference and Judgements, Adverb, Verb
  4. Mega Test:
  5. Grand Test:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a comprehensive lecture on the domain, range, and graphs of the six primary trigonometric functions. The instructor begins by introducing the topic and then systematically analyzes each function: sine, cosine, tangent, cotangent, secant, and cosecant. For each function, the video displays its algebraic definition, constructs its graph on a Cartesian coordinate system, and explicitly states its domain and range. The graphs are drawn with key points and asymptotes, and the periodic nature of the functions is highlighted. The lecture also includes a table of standard trigonometric values and a final note summarizing that all trigonometric functions are periodic.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title slide: 'Domain, Range and Graph of Trigonometric functions :'. The first function, f(x) = sin x, is introduced. The instructor begins to set up a Cartesian coordinate system, drawing the x and y axes, and labels the x-axis with key angles in radians (π/2, π, 3π/2, 2π) and the y-axis with the value 1. The function is written as y = sin x.

  2. 2:00 – 5:00 02:00-05:00

    The instructor draws the graph of y = sin x, starting from the origin and creating a smooth, periodic wave. The graph is shown to pass through key points like (0,0), (π/2,1), (π,0), (3π/2,-1), and (2π,0). The instructor then labels the domain as (-∞, ∞) and the range as [-1, 1]. The periodicity is identified as 2π, with a visual arrow indicating the length of one period.

  3. 5:00 – 10:00 05:00-10:00

    The video transitions to the second function, f(x) = cos x. The instructor draws the graph of y = cos x, which is a sine wave shifted to the left by π/2. The graph is shown to pass through (0,1), (π/2,0), (π,-1), (3π/2,0), and (2π,1). The domain is stated as R (all real numbers), the range as [-1, 1], and the periodicity as 2π.

  4. 10:00 – 15:00 10:00-15:00

    The third function, f(x) = tan x, is introduced. The instructor writes the definition tan x = sin x / cos x and notes that cos x ≠ 0. The graph is drawn with vertical asymptotes at x = (2n+1)π/2, where n is an integer. The graph consists of repeating segments between the asymptotes, passing through the origin. The domain is given as R - {(2n+1)π/2}, the range as R, and the periodicity as π.

  5. 15:00 – 20:00 15:00-20:00

    The fourth function, f(x) = cot x, is presented. The definition cot x = cos x / sin x is written, with the condition sin x ≠ 0. The graph is drawn with vertical asymptotes at x = nπ, where n is an integer. The graph consists of repeating segments between the asymptotes, passing through the origin. The domain is R - {nπ}, the range is R, and the periodicity is π.

  6. 20:00 – 25:00 20:00-25:00

    The fifth function, f(x) = cosec x, is introduced with the definition cosec x = 1 / sin x, where sin x ≠ 0. The graph is drawn with vertical asymptotes at x = nπ. The graph consists of U-shaped curves above and below the x-axis, with peaks at y=1 and troughs at y=-1. The domain is R - {nπ}, the range is (-∞, -1] ∪ [1, ∞), and the periodicity is 2π.

  7. 25:00 – 30:00 25:00-30:00

    The sixth function, f(x) = sec x, is presented with the definition sec x = 1 / cos x, where cos x ≠ 0. The graph is drawn with vertical asymptotes at x = (2n+1)π/2. The graph consists of U-shaped curves above and below the x-axis, with peaks at y=1 and troughs at y=-1. The domain is R - {(2n+1)π/2}, the range is (-∞, -1] ∪ [1, ∞), and the periodicity is 2π.

  8. 30:00 – 33:44 30:00-33:44

    The video concludes with a 'Note' slide. The instructor writes the statement: 'All trig. functions are periodic :'. This summarizes the key property of the functions discussed, reinforcing that their graphs repeat at regular intervals.

The video systematically presents a complete analysis of the six primary trigonometric functions. It follows a consistent structure for each function: definition, graph construction, and determination of domain, range, and periodicity. The visual method of drawing the graphs on a coordinate plane, highlighting key points and asymptotes, provides a clear understanding of their behavior. The lecture effectively uses the unit circle concept (implied by the use of radians and standard values) to explain the functions. The final note serves as a powerful summary, emphasizing the fundamental periodic nature of all trigonometric functions, which is a core concept in trigonometry.

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