left(0, frac{3}{4}right) is the radical centr | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The radical centre is the point of intersection of the radical axes. Since $\left(0, \frac{3}{4}\right)$ is the radical centre,it must satisfy the

Vedclass · Accepted Answer

$\left(\frac{-11}{12}, 1\right)$

Vedclass · Answer

(A) The radical centre is the point of intersection of the radical axes. Since $\left(0, \frac{3}{4}\right)$ is the radical centre,it must satisfy the equations of the radical axes $S_1-S_2=0$ and $S_2-S_3=0$. First,consider the radical axis $S_1-S_2=0$: $(x^2+y^2-2x+6y) - (x^2+y^2+2gx-2y+6) = 0$ $(-2-2g)x + 8y - 6 = 0$. Substituting $\left(0, \frac{3}{4}\right)$ into this equation: $(-2-2g)(0) + 8\left(\frac{3}{4}\right) - 6 = 0 \Rightarrow 6 - 6 = 0$. This is consistent. Next,consider the radical axis $S_2-S_3=0$: $(x^2+y^2+2gx-2y+6) - (x^2+y^2-12x+2fy+3) = 0$ $(2g+12)x + (-2-2f)y + 3 = 0$. Substituting $\left(0, \frac{3}{4}\right)$ into this equation: $(2g+12)(0) + (-2-2f)\left(\frac{3}{4}\right) + 3 = 0$ $(-2-2f)\left(\frac{3}{4}\right) = -3 $ $\Rightarrow -2-2f = -4$ $\Rightarrow 2f = 2$ $\Rightarrow f = 1$. Since $S_2$ and $S_3$ intersect orthogonally,the condition $2g_1g_2 + 2f_1f_2 = c_1 + c_2$ applies: $2(g)(-6) + 2(-1)(f) = 6 + 3$ $-12g - 2f = 9$. Substituting $f=1$: $-12g - 2(1) = 9$ $\Rightarrow -12g = 11$ $\Rightarrow g = \frac{-11}{12}$. Thus,$(g, f) = \left(\frac{-11}{12}, 1\right)$.

$\left(0, \frac{3}{4}\right)$ is the radical centre of the circles $S_1: x^2+y^2-2x+6y=0$,$S_2: x^2+y^2+2gx-2y+6=0$,and $S_3: x^2+y^2-12x+2fy+3=0$. If $S_2$ and $S_3$ intersect orthogonally,then $(g, f) =$

Similar Questions

$(a, 0)$ and $(b, 0)$ are centers of two circles belonging to a coaxial system of which the $y$-axis is the radical axis. If the radius of one of the circles is $r$,then the radius of the other circle is:

The equation of the direct common tangent of the circles $x^2+y^2-6x-4y-23=0$ and $x^2+y^2+2x+2y+1=0$ is

If $y = 2x$ is a chord of the circle $x^2 + y^2 - 10x = 0$,then the equation of the circle of which this chord is a diameter is:

If the circles $x^{2}+y^{2}=9$ and $x^{2}+y^{2}+2 \alpha x+2 y+1=0$ touch each other internally,then $\alpha$ is equal to

The equation of the radical axis of the pair of circles $7x^2+7y^2-7x+14y+18=0$ and $4x^2+4y^2-7x+8y+20=0$ is

Vedclass Test Series

Exam Paper Generator

Online Exam Module