A) \[y=0\]
B) \[x=1\]
C) \[y=-1\]
D) \[x=-1\]
Correct Answer: C
Solution :
Here we have \[{{x}^{2}}-4x-8y+12=0\] \[\Rightarrow \] \[{{x}^{2}}-4x+4-8y+8=0\] \[\Rightarrow \] \[{{(x-2)}^{2}}-8y+8=0\] \[\Rightarrow \] \[{{(x-2)}^{2}}=8\,(y-1)\] So this is the form \[{{X}^{2}}=4aY\] where \[X=x-2,\,Y=y-1\] and \[a=2\] So directrix \[x\] is given by \[Y=-a\] \[y-1=-2\] \[y=-2+1\] \[y=-1\]You need to login to perform this action.
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