## anonymous one year ago Rewrite f(x) = x2 + 9x – 16 in vertex form. Identify the axis of symmetry, vertex, and whether the vertex is a maximum or minimum help please

1. anonymous

first coordinate of the vertex is always $-\frac{b}{2a}$which is also the axis of symmetry in your case it is $-\frac{9}{2\times 1}=-\frac{9}{2}$

2. anonymous

therefore to write it in "vertex form" you can write it as $x^2+9x-16=(x+\frac{9}{2})^2+k$ to find $$k$$ replace $$x$$ in your original expression by $$\frac{9}{2}$$