1. Growth and Decay Warm-up More logs quiz and HW/INB check! Learning Objective: to use logarithms to solve real life situations.

2. Notes General Formula for Growth and Decay: y = final amount n = initial amount k = a constant (for growth k > 0, decay k < 0 t = time Ex 1 - A certain culture of bacteria will grow from 500 to 4000 bacteria in 1.5 hours. Find the constant, k, for the growth formula.

3. The time it takes for half a sample to decompose is called its half-life. Ex 2 - If the half-life of a 200-gram sample of an element is 10 years, find the constant, k.

4. Ex 3 - A piece of machinery valued at $25,000 depreciates at a steady rate of 10% yearly. When will the value be $5,000? Use the formula:

5. HW – Applications of logs wksht Summary – Logarithms are useful because… Out – none Don’t forget about POW!!