If lx + my -1 = 0 touches the circle `x^2 + y^2 = a^2` then the point (l,m) lies on the circle

If lx + my -1 = 0 touches the circle `x^2 + y^2 = a^2` then the point

1.	If lx + my -1 = 0 touches the circle `x^2 + y^2 = a^2` then the point (l,m) lies on the circle
Answer» C(0,0),r=a `d=\|(0+0-1)/sqrt(l^2+m^2)\|=a` `1/(l^2+m^2)=a^2` `l^2+m^2=1/a^2` `l^2+m^2=a^(-2)` `x^2+y^2=a^(-2)` option C is correct.

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