Lecture by Dr. Gajendra Purohit

Introduction

• Channel for engineering, BSc, and mathematics students
• Focus on higher mathematics for competitive exams
• New series on CSIR NET focusing on previous year questions

Number System

Key Concepts

• Middle Number Strategy: Take the middle number of two given numbers (e.g., 983716)
• Digit Representation: A two-digit number represented as 10x + y
• Calculating Unit Digit: Solve for y
• Option Elimination: Discard two options and check the remaining
• Perfect Square Formation: Add 9 to the product to get a perfect square

Example Problems and Strategies

• Prime Numbers: Importance of 2 as an even prime number
• Sum of Angles: In a triangle, the sum is always 180 degrees
• Divisibility Checks: Examples include 119 divisible by 17 and 121 by 11
• Square Roots: Close approximation of a number to its square root (e.g., 10201 = 101^2)
• Page Calculation:
  • Numbers from 100 to 999 are 3-digit numbers
  • Example calculation from 2019 to 1830 (subtract 189)
  • Total pages = 610 (1830/3) + 99

Student Interaction

• Encouragement to comment answers and time taken to solve questions
• Request for feedback on the helpfulness of the series

Conclusion

• Promotion of channel subscription
• Follow on Instagram for updates
• Outro with thanks and farewell