AP EAPCET 23-Aug-2021 Shift 1 Paper

End points of diameter are (4,7) and (−2,−1).
Then, equation of circle is(x−4)(x+4+(y−7)(y+1)=0
⇒x2+y2−2x−6y−15=0 ...(i)
General equation of circle is
x2+y2+2gx+2fy+c=0 ...(ii)
Compare Eqs. (i) and (ii), we obtain
g=−1,f=−3,c=−15
Now, X-intercept is given as,
AB=2√g2−c=2√1−(−19) =2√16=8
∴AB=8