Square of the length of the tangent drawn from the point $(\alpha ,\beta )$ to the circle $a{x^2} + a{y^2} = {r^2}$ is
Square of the length of the tangent drawn from the point $(\alpha ,\beta )$ to the circle $a{x^2} + a{y^2} = {r^2}$ is
- A
$a{\alpha ^2} + a{\beta ^2} - {r^2}$
- B
${\alpha ^2} + {\beta ^2} - \frac{{{r^2}}}{a}$
- C
${\alpha ^2} + {\beta ^2} + \frac{{{r^2}}}{a}$
- D
${\alpha ^2} + {\beta ^2} - {r^2}$
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