2. Exponential Functions Why study graphs of exponential functions?

3. Radioactive substance is dangerous because it decays and emits harmful radiation Radioactive substance will decay to half its mass over a period of time This period of time is called the half- life of the radioactive substance Radioactive Decay

4. Amount left is given by y=y 0 e - t where decay constant =ln 2/half-life or

5. Dr. Gordan Moore is the co-founder of Intel Moore’s Law was formulated in 1965 No. of transistors in a silicon chip doubles every 2 years 1965 - 240 transistors Pentium 4 (2000) - 42 million transistors Moore’s Law

6. or

7. Moore’s Law 1965 - 240 transistors Pentium 4 (2000) - 42 million transistors Moore’s Law: 240 x 2 0.5 t = 240 x 2 17.5 = 44 millions

8. Conclusion We use exponential graphs whenever something increases or decreases by 2 (or any factor) over the same intervals of time