MHT CET2010MathematicsCircle
The equations of the tangents to the circle x²+y²-6 x+4 y=12 , which are parallel to the straight line 4 x+3 y+5=0 , are
Options
- A3 x-4 y-19=0,3 x-4 y+31=0
- B4 x+3 y-19=0,4 x+3 y+31=0
- C4 x+3 y+19=0,4 x+3 y-31=0
- D3 x-4 y+19=0,3 x-4 y+31=0
Correct answer
C. 4 x+3 y+19=0,4 x+3 y-31=0
Step-by-step solution
Let equation of tangent be 4 x+3 y+k=0 centre of the circle is (3,-2) . Then, 9+4+12 = | 4(3)+3(-2)+k 16+9 | 6+k= 25 k=19 and -31 Hence, the tangent are 4 x+3 y+19=0 and 4 x+3 y-31=0