JCECE Engineering JCECE Engineering Solved Paper-2003

  • question_answer
    The focus of the parabola\[{{y}^{2}}=4y-4x\]is:

    A) \[(0,\,\,2)\]                        

    B) \[(1,\,\,2)\]

    C)  \[(2,\,\,0)\]                       

    D)  \[(2,\,\,1)\]

    Correct Answer: A

    Solution :

    Given equation of parabola is                 \[{{y}^{2}}=4y-4x\] \[\Rightarrow \]               \[{{y}^{2}}-4y+4=-4x+4\] \[\Rightarrow \]               \[{{(y-2)}^{2}}=-4(x-1)\] \[\Rightarrow \]               \[{{Y}^{2}}=-4X\] where\[Y=y-2,\,\,X=x-1\] The coordinates of focus are\[(-1,\,\,0)\]. \[i.e.,\] \[x-1=-1,\,\,y-2=0\] \[\Rightarrow \]               \[x=0,\,\,y=2\] \[\therefore \]Required coordinate is\[(0,\,\,2)\].


You need to login to perform this action.
You will be redirected in 3 sec spinner