Both those answers look correct to me. Why do you say that they are wrong?
I thought I solved this correctly, but my answer was marked wrong:
Here it is: Find the equations of the tangents to this curve that pass through the point (15,15).
Solution:
Substituting in the point (15,15):
After simplifying, this turns into:
Setting t=1:
is my first tangent line, which was wrong. When I graphed it, it did appear to be tangent to the curve at that point..
Setting t=-2:
also incorrect.
If someone could fix my work, I'd be very very thankful.