\(E_{AC}=\frac{k\left|q_1\right|}{CA^2}=...;E_{BC}=\frac{k\left|q_2\right|}{CB^2}=...\)
a/ \(\sum E_C=E_{AC}+E_{BC}=...\)
b/ \(\sum E_C=\left|E_{AC}-E_{BC}\right|=...\)
c/ \(AC=BC=\sqrt{2^2+2^2}=2\sqrt{2}\left(cm\right)\)
\(\sum E_C=\sqrt{E_{AC}^2+E_{BC}^2}=...\)