#### Tio Barnabe

Suppose we have the following equation, knowing that ##B## is a constant, $$\frac{dU( \theta)}{d \theta} + 2Br = 0$$ where we want to solve for ##B##. If we differentiate the above equation with respect to ##r## we get that ##B = 0##. But if we don't, we find $$B = -\frac{1}{2r} \frac{dU( \theta)}{d \theta}$$ That is, two seemgly valid but contradicting results. What am I missing here?