if the chord joining the points (2,-1)(1,-2) subtends a right angle at the center of circle then its center and - Maths - Complex Numbers

Question

if the chord joining the points (2,-1)(1,-2) subtends a right angle
at the center of circle then its center and radius are

Anuradha Sharma · Accepted Answer

Dear Student,
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"https://s3mn%20mnimgs%20com/img/shared/content_ck_images/ana_qa_image_57b2f06dbf908%20png">

Since OA = OBSo using pythagorus theorem in triangle OAB
 OA2+OB2=AB22OA2 = 1-22+-2+122=1+12=2So OA = 1 So radius = 1 unit Let centre O is x,yOA = 1 x-12+y+22=1x2+y2-2x+4y+5=0 
1Also OB = 1x-22+y+12=1x2+y2-4x+2y+5=0
2Now subtracting 1-2 2x+2y=0 x = -y Putting this in equation 1 2x2-2x-4x+5=02x2-6x+5=0 x = 6±36-402 but it is coming out to be imaginary so kindy check the question
 Regards

if the chord joining the points (2,-1)(1,-2) subtends a right angle at the center of circle then its center and radius are