Day 32 in Mat122

Today:

• Return Exam 2 (for good!)
  • Curve: the better of
    • adding 3 points to your score -- (x+3)*2 -- or
    • your score obtained using only the best four grades (total of 4, times 2.5).

• Homeworks:
  • 7.2 due Thursday, 12/6
  • 7.3 due Friday, 12/7
  • 7.4 due Monday, 12/10

• Section 7.3: logarithmic functions
  • 

  • The laws of logarithms are reflections of the properties of exponentials:

    

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  • Examples:
    • 45-50, p. 365, and draw!
    • 80, 86, 94, p. 365
    • 108, p. 366
    • 109, p. 366

• Section 7.4: applications of exponential growth and decay
  • Exponentials satisfy a very important differential equation:
    f  '  (t) = kf(t)

  • Doubling time: the time it takes for a growing exponential function to double in size.
  • Half life: the time it takes for a dying exponential function to halve in size.
  • Examples:
    • #3, p. 371
    • #9, p. 372
    • #16, p. 372
    • #18, p. 372
    • #25, p. 373