The normal to the curve $y(x-2)(x-3)=x+6$ at the point where the curve intersects the y-axis passes through the point
Answer & explanation
Correct answer: option 2
The equation of the curve is
$y(x-2)(x-3)=x+6$ ......(i)
It intersects y-axis at x = 0. Putting x = 0 in (i), we obtain y = 1. So, the point where (i) cuts y-axis has the coordinates (0, 1).
From (i), we obtain
$y=\frac{x+6}{x^2-5 x+6}$
Differentiating with respect to x, we obtain
$\frac{d y}{d x}=\frac{\left(x^2-5 x+6\right)-(x+6)(2 x-5)}{\left(x^2-5 x+6\right)^2}$
∴ $\left(\frac{d y}{d x}\right)_{(0,1)}=\frac{6-(-30)}{36}=1$
The equation of the normal at (0, 1) is
$y-1=-1(x-0)$ or, $x+y-1=0$
Clearly, it passes through $\left(\frac{1}{2}, \frac{1}{2}\right)$.