Question

find constant C of x^2+11x+c (complete the square) in the xy plane has its vertex on the line y=x

Answer 1

i gotta run but the idea is this
vertex has first coordinate
\[-\frac{11}{2}\] and second coordinate what you get when you plug that in
since the vertex is on the line
\[y=x\] you can set that result equal to
\[-\frac{11}{2}\] and solve for c

Answer 2

ty ^^

Answer 3

c=99/4