Err. My hind was that the vector <6,6,-8> is just a scaled version of <3,3,-4>, and we can use <3,3,-4> instead of <6,6,-8> (or you can equivalently just multiply T(t) by 2 to get

. It doesn't matter which way you do it.

Or course none of this matters iy you do not know WHY you are doing these things. You know that the vector function T(t) at the point P will be orthgonal to your normal plane, as would ANY vector that is parallel to the vector T(t) at point P. <3,3,-4> is parallel to <6,6,-8>, so you can use <3,3,-4> instead since that 3 matches up with the 3 in T(t).

But now what do you do? It is asking for a POINT, not a vector. We'll we know the T(t) is parallel to <3,3,-4> or

. See if you can take it from there.