prove that the locus of a centre of a circle which intercepts a chord of given length2aon the axis of x and passes through a given point on the axis of y distant b from the origin is the curve x2-2yb+b2 = a2 trace this parabola.

Dear student
The equation of circle is:x-x12+y-y12=r2Here x-axis intercept=2a2x12-x12+y12-r2=2aSquaring both sides, we getx12-x12+y12-r2=a2x12-x12-y12+r2=a2So, we get y12=r2-a2It passes through 0,bSo, we get 0-x12+b-y12=r2x12+b-y12=r2x12+b2+y12-2by1-r2=0x12+b2+r2-a2-2by1-r2=0x12+b2-2by1-a2=0So, locus of x1,y1 will be x2-2by+b2=a2Hence proved.
For different values of a and b ,the  parabola is traced as:

Regards
 

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