The Ramberg Osgood equation relates the stress in an elastic plastic material to the strain.
$\epsilon_a=\frac{\sigma_a}{E}+(\frac{\sigma_a}{A})^\frac{1}{n}$
$E$ and $A$ are both bigger than $\sigma_a$
As for $n$ it should be smaller than 1.
The reason I want to solve this equation's reciprocal is because we sometimes obtain $\epsilon_a$ and we need to solve for $\sigma_a$
Any help would be appreciated, because I can't seem to find a way to solve it with my current math tools.
Note: I know this can be solved numerically with countless ways, but I was searching for a closed formula