Finding Maxima & Minima (Practice Questions Set 1)
Duration: 10 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- General Intelligence & Reasoning: Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Logical Sequence Of Words, Syllogisms, Venn Diagram, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Data Sufficiency, Puzzle Solving (Puzzles), Data Arrangement, Cubes & Dices, Calendar, Clock, Arithmetic, Number System, HCF LCM, Verbal Analogy (Word Based Analogy), Visual Recognition and Figure Completion, Paper Folding and Cutting, Transformation of Shapes, Clocks and Calendars, Direction Sense, Cubes and Dice, Patterns in Two-Dimensional Figures, Seating Arrangements, Analogy and Classification, Logical Deduction and Induction, Alphabet and Word Tests, Mathematical Operations, Series Completion, Simplification and Approximation, Coding and Decoding, Numerical Reasoning, Assembling and Grouping of Shapes, Three-Dimensional Patterns and Visualization, Vocabulary, Number System, Averages, Mixtures and Alligation, Simple and Compound Interest, Percentages, Algebra, Speed, Time and Distance, Seating and Arrangement Puzzles, Traverse Surveying, Order, Ranking and Sequence, Constraint Puzzles, Syllogisms and Venn Diagrams, Reading Comprehension, Critical Reasoning, Permutations and Combinations, Narrative Sequencing, Project Monitoring, Resources and Safety, Profit, Loss and Discount, Ratio and Proportion, Time and Work, Mensuration, Data Interpretation, Powers, Surds and Logarithms, Sequences and Series, Articles and Determiners, Sentence Completion, Data Sufficiency, Blood Relations, Simple Interest and Compound Interest, Mixture and Alligation, Sequence and Series (Series), Speed Time and Distance, Algebra, Profit and Loss, Powers and Exponents (Surds and Indices), Permutation and Combination
- General Awareness: Physics, Chemistry, Biology, History, Geography, Polity, Indian Economy, Environment, Static General Knowledge, GK- Current Affairs, Artificial Intelligence, MS Office Applications, Terms & Abbreviations, Keyboard Shortcuts, Evolution of Indian Banking (Banking & Financial Awareness), Emerging Tech Trends
- Engineering Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Linear Algebra, Calculus, Probability, Statistics, Signal Space and Optimum Detection, Probability, Statistics
- Digital Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Floating Point Rep, Number Systems and Codes, Registers and Counters, Boolean Algebra and Logic Gates, Microprocessors and Microcontrollers, Logic Families and CMOS Logic, Microprocessors, Logic Gates and Boolean Algebra, Minimization of Boolean Functions, Timing, Hazards and Testing, Logic Families, Combinational Logic Design, Arithmetic Circuits, Waveform Generators and Timer Circuits, Semiconductor Memories and Programmable Logic Devices, Combinational Logic Circuits, Latches and Flip-Flops, Finite State Machines, Sequential Circuits and State Machines, Minimization of Boolean Functions, Arithmetic Circuits, Latches and Flip-Flops, Number Systems and Codes, Registers and Counters
- Computer Organisation & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Programming the Basic Computer, Register Transfer and Microoperations, Semiconductor Memories and Programmable Logic, Processor Organization and Instructions, Memory Hierarchy and Input/Output, Registers and Counters
- Programming & Data Structures: 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, HTML Basics, OOPS with C++, Java, Object Oriented Technology
- Databases: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, Database Security & Authorization
- Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos
- Theory of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Complexity Theory
- Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment
- Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Security, Windows OS, Distributed Systems, Unix OS, Linux OS
- Computer Networks: Introduction to CN, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware Basics, Data Communication, Website, Browser & Services, Web Design & Development, Network Security, Cyber Threats and Malware Attacks, Cyber Safety and Security
- Full Length Mock Tests:
- Sectional Tests:
- Paper 2 - Full-length Mock Tests:
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This educational video provides a comprehensive lecture on finding local maxima and minima using calculus techniques. The instructor, Yash Jain Sir, systematically analyzes four specific functions: the absolute value function $f(x) = |x|$, the linear function $f(x) = x$, the quadratic function $f(x) = x^2$, and the cubic function $f(x) = x^3$. For each function, he employs a combination of graphical visualization and analytical derivative tests. The lesson covers identifying stationary points where the first derivative is zero, handling points where the derivative is undefined, and applying the second derivative test to classify critical points. The progression moves from simple non-differentiable cases to standard polynomial functions, culminating in a discussion on points of inflection where higher-order derivatives are required.
Chapters
0:00 – 2:00 00:00-02:00
The video begins with an introduction to the topic, displaying a list of functions on the whiteboard: $f(x) = |x|$, $f(x) = x$, $f(x) = x^2$, and $f(x) = x^3$. The instructor starts the analysis with the absolute value function, $f(x) = |x|$. He draws a V-shaped graph on the coordinate plane, clearly marking the vertex at the origin $(0,0)$. He identifies the global minimum value as $0$ and notes that the maximum value approaches positive infinity ($+\infty$). A key concept is introduced regarding the derivative at the vertex. The instructor writes that while $f'(x) = 0$ is a condition for extrema, in this specific case, the derivative $f'(x)$ is not defined at $x=0$. This demonstrates that a function can have a minimum even if the derivative does not exist at that point, highlighting the importance of checking for non-differentiable points.
2:00 – 5:00 02:00-05:00
Next, the instructor transitions to the linear function $f(x) = x$. He sketches a straight line passing through the origin with a positive slope. He calculates the first derivative, writing $f'(x) = 1$. To find critical points, he attempts to set the derivative to zero, writing $f'(x) = 0$. However, he immediately points out the contradiction $1 eq 0$, indicating that there are no stationary points for this function. Consequently, he concludes that the function has no local maxima or minima. He writes down the range behavior, stating that the minimum is negative infinity ($-\infty$) and the maximum is positive infinity ($+\infty$). This section reinforces the idea that monotonic functions do not possess local extrema.
5:00 – 10:00 05:00-10:00
The lecture proceeds to the quadratic function $f(x) = x^2$. The instructor draws a standard parabola opening upwards. He computes the first derivative as $f'(x) = 2x$. Setting this to zero yields the equation $2x = 0$, which gives the stationary point $x = 0$. To determine the nature of this point, he applies the second derivative test. He calculates the second derivative, $f''(x) = 2$. Evaluating this at the stationary point, he finds $f''(0) = 2$. Since $2 > 0$, the second derivative is positive, which confirms that the point $x=0$ is a local minimum. He circles the result and writes "minimum" next to it, solidifying the connection between the sign of the second derivative and the concavity of the graph.
10:00 – 10:12 10:00-10:12
Finally, the instructor analyzes the cubic function $f(x) = x^3$. He displays a graph of the function on a computer screen to show its S-shape. He calculates the first derivative $f'(x) = 3x^2$ and sets it to zero to find the stationary point at $x=0$. He then checks the second derivative, $f''(x) = 6x$, which evaluates to $0$ at $x=0$. Since the second derivative is zero, the test is inconclusive. He proceeds to calculate the third derivative, $f'''(x) = 6$. Since $f'''(0) = 6 eq 0$ and the order is odd, he explains that this indicates a point of inflection rather than a maximum or minimum. He concludes that for $x^3$, the minimum is $-\infty$ and the maximum is $+\infty$. The video ends with a "Thanks for watching" screen.
The video effectively demonstrates a hierarchical approach to finding extrema. It starts with the absolute value function to introduce non-differentiable points, moves to a linear function to show cases with no critical points, uses a quadratic function to illustrate the standard second derivative test for a minimum, and finishes with a cubic function to explain how to handle cases where the second derivative vanishes, requiring higher-order derivatives. This progression builds a complete toolkit for analyzing polynomial and piecewise functions for local extrema.

