### Home > CCAA8 > Chapter 9 Unit 10 > Lesson CCA: 9.1.2 > Problem9-21

9-21.

For each quadratic function below, use the idea of completing the square to write it in graphing form. Then state the vertex of each parabola.

1. $f(x)=x^2+4x+5$

Put it into graphing form and from there figure out the vertex.

$f(x)=(x+2)^2+1$,
vertex: $(−2,1)$

1. $f(x)=x^2−6x$

See part (a).

1. In both graphs, does the vertex represent the maximum or minimum value of the parabola?

Is the vertex the highest (maximum) or lowest (minimum) point on the graph?