Q.

Let A be the point (1, 2) and B be any point on the curve x2+y2=16. If the centre of the locus of the point P, which divides the line segment AB in the ratio 3 : 2, is the point  C(α,β), then the length of the line segment AC is          [2023]

1 255  
2 355  
3 655  
4 455  

Ans.

(2)

Since, P(h,k) divides AB in the ratio 3:2.

So, 12cosθ+25=h and 12sinθ+45=k

12cosθ=5h-2                                        ...(i)

and 12sinθ=5k-4                                      ...(ii)

Squaring (i) and (ii) and then adding, we get  

144=(5h-2)2+(5k-4)2

(x-25)2+(y-45)2=14425

Centre (25,45)C(α,β)

AC=(1-25)2+(2-45)2 =925+3625=355