ELI5: Explain Like I'm 5

Cousin's theorem

Cousin's theorem is like when you share toys with your cousin. Let's say you have a toy truck and your cousin has a toy car. You both want to play with both toys, so you decide to trade.

In math (which is like playing with numbers), Cousin's theorem applies to something called complex functions. Complex functions are like toys that do different things when you push buttons or turn knobs.

Cousin's theorem says that if you have two different complex functions that are connected or related to each other in a special way, you can trade parts of one function with parts of the other function to find out new things. It's like trading your toy truck wheels with your cousin's toy car wheels to see how they work together.

Scientists and mathematicians use Cousin's theorem to help them solve difficult problems and understand how complex systems work. So, just like you and your cousin sharing toys, Cousin's theorem helps complex functions share parts and work together to make new discoveries.