We are given the quadratic:
[tex]f(x)=x^2-8x+15[/tex], with a=1, b=-8, c=15.
We know that the x-coordinate of the vertex, which is the point where the line of symmetry passes through is
[tex]\displaystyle{ -\frac{b}{2a} [/tex].
Thus, the x-coordinate of the vertex is [tex]-\frac{b}{2a} =-\frac{-8}{2\cdot1}= \frac{8}{2}=4 [/tex].
Thus, the line of symmetry is x=4.
Answer: B. The line of symmetry should have been 4 instead of –4.
