3rd question please
3. The nearest point on the circle x2+y2-6x+4y-12=0 from (-5,4) is 
1)(1,1)                                         2)(-1,1)
3)(-1,2)                                        4)(-2,2) 

 

Dear Student,
Please find below the solution to the asked query:

We havex2+y2-6x+4y-12=0..iCentre is Q3,-2P-5,4Shortest or longest distance is always found along normal and nomralof circle  passes through centre.Hence nearest point will be found along line PQ whose equation isy+2=4+2-5-3x-3y+2=6-8x-3y+2=-34x-3y=-34x+94-2y=-34x+14=-3x+14...iiSolve i and iix2+-3x+142-6x+4-3x+14-12=0Solving the above quadratic equation we getx=-1 and x=7y=-3x+14When x=-1y=3+14=1Hence -1,1When x=7y=-21+14=-5Hence 7,-5By distance formula you can easily see that -5,4 is nearer to -1,1Hence option2 is correct.Note: 7,-5 is farthest from -5,4

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  • 1
Hi Krishna, simply plug the points given in circle equation and check whether it satisfies.
Doing so, we come to know that (-1,2) is the one
Hence right option is (3) as marked by a slash seen in the paper
Actually (-5,4) is nothing to do with this kind of objective question
 
  • -1
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