Now I know the rules about this one, But I can't work out the second half of the sum,

1st half:

1. Find the value of such that the line with equation is a tangent to the parabola with equation

the determinant = 0 then there is only one intersection (tangent)

through DOPS

therefore

Now this is the part, I don't understand,

2. Find the possible values of c such that the line with equationtwice intersects the parabola with equation

Any help would be much appreciated,

Thanks,

22upon7