0. The locus of P such that area of APA-12units, where A(2,3) and B(-4

1.	0. The locus of P such that area of APA-12units, where A(2,3) and B(-4,5) is(A) (x+3y-1(x+3y-23) 0(x +3y+(x+3y- 23)(C) (3x +y-13x+y-23) 0(D) (3x + y+13x + y+23) 0END OF TEST PAPER
Answer» Let P be a point (x,y) on the locus. Formula for area of a triangle with vertices at (x1,y1), (x2,y2) and (x3,y3) is given by 1/2{x1(y2-y3) +x2(y3-y1)+x3(y1-y2)}. Taking A as (x1,y1), B as (x2,y2) and P as (x3,y3) we get area of triangle PAB is 1/2{2(5-y)-4(y-3)+x(3–5)}=12 given Simplifying, 10–2y-4y+12–2x=24 or -2x-6y-2=0 or x+3y+1=0.

0. The locus of P such that area of APA-12units, where A(2,3) and B(-4,5) is(A) (x+3y-1(x+3y-23) 0(x +3y+(x+3y- 23)(C) (3x +y-13x+y-23) 0(D) (3x + y+13x + y+23) 0END OF TEST PAPER

Answer»

Let P be a point (x,y) on the locus.

Formula for area of a triangle with vertices at (x1,y1), (x2,y2) and (x3,y3) is given by

1/2{x1(y2-y3) +x2(y3-y1)+x3(y1-y2)}. Taking A as (x1,y1), B as (x2,y2) and P as (x3,y3)

we get area of triangle PAB is 1/2{2(5-y)-4(y-3)+x(3–5)}=12 given

Simplifying, 10–2y-4y+12–2x=24 or -2x-6y-2=0 or x+3y+1=0.