Circles ${(x + a)^2} + {(y + b)^2} = {a^2}$ and ${(x + \alpha )^2}$ $ + {(y + \beta )^2} = $ ${\beta ^2}$ cut orthogonally, if
Circles ${(x + a)^2} + {(y + b)^2} = {a^2}$ and ${(x + \alpha )^2}$ $ + {(y + \beta )^2} = $ ${\beta ^2}$ cut orthogonally, if
- A
$a\alpha + b\beta = {b^2} + {\alpha ^2}$
- B
$2(a\alpha + b\beta ) = {b^2} + {\alpha ^2}$
- C
$a\alpha + b\beta = {a^2} + {b^2}$
- D
None of these
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