Question

which equation was used by Einstein to describe the relationship between energy and mass

Answer 1

The Equivalence of mass and energy

Answer 2

The most famous equation E= mc^2 is used still today for deriving relation between mass and energy.... But when it was discovered in 1905 it was originally discovered as m= E/c^2 but later scienctist evolved it for finding energy........ It is known as mass energy equivalence