What value of c makes the polynomial below a perfect square trinomial? x2 + 18x + c?

Me i need ! find the asymptote and determine the end behavior of the function from the graph. the asymptote of the function is= blank 1 . for very high x-values,y =blank 2 options for blank 1 x=2 x=-2 x=3 x=-3 blank 2 options moves towards negative infinity moves toward the horizontal asymptote moves toward the vertical asymptote moves toward positive infinity