The following equation is from a force triangle from statics (mechanics) and was written by applying the law of cosines.
$F^2=F_R^2+a-bF_R$ (1)
where a and b are constants, $F_R$ is the resultant force and $F$ is a component. The question I was trying to solve tells me that the resultant force is a minimum which means $\frac{dF_R}{dF}=0$. When I implicitly differentiate the equation(1), the derivative function is also an implicit one. I know the problem can be solved using another equation which explicitly expresses $F_R$ but I wonder if eqn (1) can be expressed explicitly. My question is:
How can I leave $F_R$ alone on one side of eqn(1)?
