I have a function: $$L_R=4*\pi*5*R^2*J$$ I have error values for this R and J. So I want to find the error of $$L_R$$
Should I go for:$$L_R=f$$ $$df=L_{R_{error}}=\frac{\partial{f}}{\partial{x}}dx+\frac{\partial{f}}{\partial{y}}dy$$ where $$x=R$$$$y=J$$$$dx=J_{error}$$$$dy=R_{error}$$
However, i have no idea what their coefficients would be or how to calculate the error of $$L_R$$