It’s time for us all to understand the Exponential Function. One of the hallmarks of COVID-19 is its exponential nature, with numbers of infected currently doubling about every 4 days in the US.

Understanding how exponential growth works is key, experts say, because it sheds light on why they're so worried about the latest wave of cases sweeping parts of the United States.

The country is facing another cycle of the Covid-19 pandemic, and it may be the hardest yet, former Food and Drug Administration Commissioner Dr. Scott Gottlieb said Monday.