JEE Main 2022 · 26 Jul · Shift 2 · Mathematics Q13

← JEE Main 2022 · 26 Jul · Shift 2

MathematicsSingle correct+4 / -1Question 13 of 90

Let the abscissae of the two points P and Q on a circle be the roots of $x^2-4x-6=0$ and the ordinates of P and Q be the roots of $y^2+2y-7=0$ . If PQ is a diameter of the circle $x^2+y^2+2ax+2by+c=0$ , then the value of $(a+b-c)$ is ______.

Answer and worked solution

Official answer: A

Circle on PQ as diameter. $(x-x_1)(x-x_2)+(y-y_1)(y-y_2)=0$ is $x^2-4x-6+y^2+2y-7=0$ .

So $a=-2$ , $b=1$ , $c=-13$ and $a+b-c=12$ . (A)

Topics:Equation of a circle Roots and coefficients

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JEE Main 2022 · 26 Jul · Shift 2, Mathematics question 13