[tex] p= \dfrac{c^2}{c^2 + 4}[/tex]
[tex] c^2 p + 4 p = c^2 [/tex]
[tex] 4 p = c^2 - c^2 p = c^2(1-p)[/tex]
[tex]c^2 = \dfrac{4p}{1-p}[/tex]
[tex]c = \pm \sqrt{\dfrac{4p}{1-p} } = \pm 2 \sqrt{\dfrac{p}{1-p} } [/tex]
Answer: [tex]\quad c = \pm 2 \sqrt{\dfrac{p}{1-p} [/tex]
