What is it called when you take a value and perform an operation on it and return the identical value?
The formula to convert Celsius to Fahrenheit is
Vice versa is:
If you use the value -40, you get the same result. 9/5 is 1.8 in decimal
1.8*(-40)+32 = -40
I dunno why this works out this way and would be interested for someone to explain how and why it does.