A circle has its equation (x ~ 9)2 + (y + 1)2 = 117. The point A (3,k) lies on the circle; where k > 0. (a) Calculate the value of k (b) Find the equation of the tangent to this circle at the point A: (c) Show clearly that this tangent passes through the centre of the circle with equation x? y? + 6x 8y 12 = 0.A circle has its equation (x ~ 9)2 + (y + 1)2 = 117. The point A (3,k) lies on the circle; where k > 0. (a) Calculate the value of k (b) Find the equation of the tangent to this circle at the point A: (c) Show clearly that this tangent passes through the centre of the circle with equation x? y? + 6x 8y 12 = 0.