Understanding Negative Exponents Clearly

Aug 14, 2024

Lecture on Exponents

Introduction

  • Second video on exponents.
  • Introduction to negative exponents and exponents on fractions.

Review of Basic Exponents

  • Example: 3 squared (3^2) = 9
  • 3 multiplied by itself two times: 3 x 3 = 9

Negative Exponents

Misconception

  • Natural logic: Positive exponent results in a positive number; negative exponent results in a negative number. This is incorrect.

Solving Negative Exponents

  • Rule: A negative exponent in the numerator becomes a positive exponent in the denominator.
  • Example: 3^(-2)
    • Rewrite: 1 x 3^(-2)
    • Solution: 1 / (3^2) = 1 / 9

Negative Exponent in the Denominator

  • Rule: A negative exponent in the denominator becomes a positive exponent in the numerator.
  • Example: 1 / 3^(-2)
    • Rewrite: 3^2
    • Solution: 3 x 3 = 9

Negative Numbers with Negative Exponents

  • Example: 6 x (-3)^(-2)
    • Rewrite: 6 / (-3)^2
    • Simplified: Negative 3 multiplied by itself: (-3) x (-3) = 9
    • Simplified Fraction: 6 / 9 = 2 / 3

Fractions with Negative Exponents

  • Example: (3/4)^(-2)
    • Multiply by 1: 1 x (3/4)^(-2)
    • Rewrite: 1 / (3/4)^2
    • Simplified: (3/4) x (3/4) = 9/16
    • Final Simplification: 1 / (9/16) = 16/9

Conclusion

  • Clarification on negative exponents in fractions.
  • Preview: Next video will cover properties of exponents.
  • Encouragement to stay tuned for more videos.