question_answer

If the circle \[{{(x-h)}^{2}}+{{(y-k)}^{2}}={{r}^{2}}\] touches the curve \[y={{x}^{2}}+1\]at a point (1, 2), then the possible locations of the points (h, k) are given by                                           [AMU 2000]

A)            \[hk=5/2\]                                

B)            \[h+2k=5\]

C)            \[{{h}^{2}}-4{{k}^{2}}=5\]   

D)            \[{{k}^{2}}={{h}^{2}}+1\]