Maths F.5 (circle )

1. Find the equations of the tangents to the circle x^2+y^2 -6x-2y =0 with slope 11/3.

ans : y= 1/3x+10/3 , y=1/3x -10/3

2. If the radius of the circle 2x^2+2y^2-6x+8y+k=0 is the square root of 19 over 2 , find the value of k

3. The equation of circle C is (x+3)^2 +y^2 =40 and the equation of straight line L is 3x-y +29=0
(i)If B is point on C and AB is diameter, find the equation of AB.

ans : x+3y+3=0
(ii)find the equation of the straight line which touches C at B.

ans: 3x-y-11=0