Original equation is \(P=kx^{2}\)
So, \(kx^{2} =P\) and
\(k=\frac{P}{x^{2} }\)
If we compare this equation with the given options, we can easily find that this matches with the last one \(k=\frac{p}{2x^{2} }\) with P = p/2.
Hence, correct option is \(k=\frac{p}{2x^{2} }\).
