Circle And System Of Circles Question 95
Question: The equation of the circle whose centre is (1, -3) and which touches the line $ 2x-y-4=0 $ is
Options:
A) $ 5x^{2}+5y^{2}-10x+30y+49=0 $
B) $ 5x^{2}+5y^{2}+10x-30y+49=0 $
C) $ 5x^{2}+5y^{2}-10x+30y-49=0 $
D) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
Radius of circle is $ | \frac{2+3-4}{\sqrt{5}} |\ =\frac{1}{\sqrt{5}} $ Therefore, equation is $ {{(x-1)}^{2}}+{{(y+3)}^{2}}=\frac{1}{5} $ or $ x^{2}+y^{2}-2x+6y+1+9=\frac{1}{5} $ or $ 5x^{2}+5y^{2}-10x+30y+49=0 $ .
BETA
