# 9 – Exponential and Logarithmic Functions

• What happens when you or a loved one gets sick?
• What might have caused the illness, and what might you have to do to get well again?
• Imagine getting together with all of your friends.
• And all of their friends.
• And all of their friends’ friends.
• And all of their friends’ friends’ friends.
• Like putting rockets on rockets on rockets on rockets, exponential growth is all about going faster, faster, faster!
• From infectious outbreaks and nuclear reactions to medical treatments and computer algorithms, exponents and logarithms are essential for living in the 21st century.
• Logarithms are the inverses of exponential functions, and just as important. Logarithms help measure tremors deep within the earth.
• Your wireless devices uses logarithms to find the strongest wi-fi signal.