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Quadratic Equations and Complex Numbers Overview

Jun 4, 2025

Study Guide Unit 7B

Solving Quadratic Equations using the Quadratic Formula

  1. Equation: (x^2 + 2x - 3 = 0)

    • Solutions: (x = 1), (x = -3)
  2. Equation: (3x^2 + 5x + 1 = 0)

    • Solutions:
      • (x \approx 0.23)
      • (x \approx 1.43)
  3. Equation: (2x^2 - 4x + 5 = 0)

    • Solutions:
      • (x \approx 0.87)
      • (x \approx 2.87)
  4. Equation: (5x^2 + 6x - 5 = 0)

    • Quadratic formula setup is complex, detailed steps omitted.

Other Methods to Solve Quadratics

  1. Equation: (3x^2 - 5x - 12 = 0)

    • Solution requires alternative methods not detailed here.
  2. Equation: (4(x - 3)^2 + 13 = 209)

    • Solution requires alternative methods not detailed here.
  3. Equation: (12x^2 + (2x + 1)^2 = 372)

    • Solution requires alternative methods not detailed here.

Simplifying Square Root Expressions

  1. (\sqrt{68})
  2. (\sqrt{396})
  3. (\sqrt{9136})
  4. (\sqrt{24})
  5. (\frac{-37}{\sqrt{5}})
  6. (\frac{2}{\sqrt{65}})

Imaginary and Complex Numbers

  1. Simplify: (\sqrt{-81})
  2. Simplify: (\sqrt{-625})
  3. Expression: ((9i)^2)
  4. Expression: ((3 + 2i) + (7 + 6i))
  5. Expression: ((10 + 5i) - (10 - 8i))
  6. Expression: ((3 + 2i)(4 + 5i))
  7. Expression: ((4 + 5i)^2)
  8. Expression: ((7 - 2i)^2)

Additional Problems

  1. Equation: (x^2 - 4x + 10)
    • Additional manipulation or solving required.
  2. Expression to Simplify: (8i^2 + 15i)
  3. Expression to Simplify: (24 - 213i - 5i^2)

Notes:

  • The lecture focuses on solving quadratic equations using various methods, including the quadratic formula.
  • Simplifying square roots and working with imaginary and complex numbers is emphasized.
  • Some problems were noted with missing steps, indicating alternative methods need to be applied.
  • The content also includes specific examples of complex number operations.