This is the full question:

Find the equation of the pair of lies that pass through the origin and through the points of intersection of the line \(\displaystyle y=\lambda(x+1)\) and the circle \(\displaystyle (x-2)^2+(y-2)^2=9\). If these lines are perpendicular find \(\displaystyle \lambda\). For what value of [/tex]\lambda[/tex] do these lines coincide? Deduce the equations of the tangents to the circle from the point (1,0).

This is the last part. I've done all the rest. For when the lines coincide i do have a small problem.

The equation of the line pair is:

\(\displaystyle y^2(\lambda^2-4\lambda-1)+2\lambda xy(2\lambda -1)+4\lambda^2x^2=0\)

If the lines coincide then \(\displaystyle h^2-ab=0\)

\(\displaystyle \lambda^2(2\lambda -1)^2-(\lambda^2-4\lambda-1)(4\lambda^2)=0\)

I worked it out and found \(\displaystyle \lambda=0, -\frac{5}{12}\)

Answer says \(\displaystyle \lambda=\infty, -\frac{5}{12}\)

These two are the problems I have