How do i solve 9c? Ive done 9a and 9b.

Question 9 [Guided question for a line intersecting a sphere] Consider the line represented by the vector equation (A ) = - 2 + A and the sphere centred at (2, -1,3) with radius 3. Write down the vector equation of the line in the form r ( 1 ) = f ( A ) i + g ( A ) j + h (A)k. Write down the Cartesian equation of the sphere. Substitute the i, j and k components into the equation of the sphere to show that 712-81 +1 = 0 and hence solve for 1. Hence, find the two points where the line intersects the sphere. What can we say if the quadratic in terms of A has no real roots? How about one real root