• # question_answer The equations of the circles which touch both the axes and the line $x=a$ are A)  ${{x}^{2}}+{{y}^{2}}\pm ax\pm ay+\frac{{{a}^{2}}}{4}=0$ B) ${{x}^{2}}+{{y}^{2}}+ax\pm ay+\frac{{{a}^{2}}}{4}=0$ C)  ${{x}^{2}}+{{y}^{2}}-ax\pm ay+\frac{{{a}^{2}}}{4}=0$ D)  None of these

$\Rightarrow$ ${{\left( x-\frac{a}{2} \right)}^{2}}+{{\left( y\pm \,\frac{a}{2} \right)}^{2}}={{\left( \frac{a}{2} \right)}^{2}}$ $\Rightarrow$ ${{x}^{2}}+{{y}^{2}}-ax\pm \,ay+\frac{{{a}^{2}}}{4}=0$