A) \[4f\]
B) \[4f\]
C) \[5f\]
D) \[5f\]
Correct Answer: B
Solution :
Equation of circle which touches x-axis and coordinates of centre are (h, k), is \[{{(x-h)}^{2}}+{{(y-k)}^{2}}={{k}^{2}}\] \[\therefore \]It is passing through (-1, 1), then \[{{(-1-h)}^{2}}+{{(1-k)}^{2}}={{k}^{2}}\] \[\Rightarrow \]\[{{h}^{2}}+2h-2k+2=0\] \[\because \]For real circle, \[D\ge 0\]\[\Rightarrow \]\[2k-1\ge 0\] \[\Rightarrow \]\[k\ge \frac{1}{2}\]You need to login to perform this action.
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