Take the 2-minute tour ×  I was practicing some basic math and I
faced a question that I have no idea what does it requires me to
do. Consider this simple function:  $$f(x) = x^2-5x-12$$  Part a
and b where pretty easy. I tried to solve part C as you can see
below. Unfortunately I cant imagine what has been asked in part
D. What does coincident points of intersection mean? (Literally
intersection means cutting each other and Coincident means on
top of another AFAIK) Any help/explanation would be appreciated!
Part C:  The point at which the line through $(1,-15)$ with
slope $m$ cuts the graph of $f(n)$.  $$m=f'(n)=f'(1)=-1$$
$$y-y_1 = m(n-n_1)=>y+15=-1(n-1)$$ $$=>y=-n+1-15$$  Part D:  The
values of m such that the points of intersections found in $c$
are coincident.  share|improve this question Coincident means
that the two results you should get in part (c) are the same.
Something must be wrong because you only seem to be getting a
single result (in fact I don't understand what you're doing
there at all). – 