माना `q_(1)+q_(2)=q` अर्थात `q_(2)=q-q_(1)`
प्रतिकर्षण बल `F=(1)/(4pi epsilon_(0)).(q_(1)(q-q_(1)))/(r^(2))`
अधिकतम बल के लिए, `" "(dF)/(dq_(1))=0`
या `" "(d)/(dq_(1))([q_(1)(q-q_(1))])/(4pi epsilon_(0)r^(2))=0`
या`" "(d)/(dq_(1))[q_(1)(q-q_(1))]=0, [because 4pi epsilon_(0)r^(2)=1]`
या `" "(d)/(dq_(1))[qq_(1)-q_(1)^(2)]=0`
या `" "q-2q_(1)=0`
या `" "q_(1)=(q)/(2)`
अतः `" "q_(2)=q-q_(1)=a-(q)/(2)=(q)/(2)`
अर्थात `q_(1)=q_(2)=(q)/(2)`.