JEE Main 2015 · 4 Apr · Shift 1 · Mathematics Q72

MathematicsSingle correct+4 / -1Question 72 of 90

The normal to the curve, $x^2+2xy-3y^2=0$ , at (1, 1) :

does not meet the curve again.

meets the curve again in the second quadrant.

meets the curve again in the third quadrant.

meets the curve again in the fourth quadrant.

Answer and worked solution

Official answer: D

The curve factors as $(x+3y)(x-y)=0$ : two lines. (1, 1) lies on $y=x$ , whose normal there is $x+y=2$ .

It meets the other line, $x+3y=0$ , at $(3,-1)$ : the fourth quadrant.

JEE Main 2015 · 4 Apr · Shift 1, Mathematics question 72