2.
State the necessary and sufficient condition for lx+my+n=0 to be a normal to the circle
x + y2 +2gx + 2 fy+c=0
Answers
We have to state the necessary and sufficient condition for lx + my + n = 0 to be a normal to the circle x² + y² + 2gx + 2fy + c = 0.
solution : any line will be normal to the circle only if line passing through centre of the circle.
equation of circle is x² + y² + 2gx + 2fy + c = 0
so centre of circle = (-g, - f)
so equation of line must satisfy the centre of circle.
i.e., l(-g) + m(-f) + n = 0
⇒lg + mf = n
Therefore the required condition is lg + mf = n.
also read similar questions : From a point on the circle x² + y2 + 2gx + 2y + c = 0 two tangents are drawn to the
circle x + y + 2gx + 2fy + c sin^2 a...
https://brainly.in/question/10873989
If the circle x2+y2+2gx+2fy+c=0 touches x-axis at (x1,0) then x1 is the repeated root of?
https://brainly.in/question/17360464
Step-by-step explanation: