### Home > A2C > Chapter 8 > Lesson 8.1.3 > Problem8-42

8-42.

Write the quadratic function in problem 8-41 in graphing form and sketch its graph.

Factor out the $3$ and separate it from the constant.

Complete the square.
Add the value that completes the square inside the parentheses
and subtract it outside.
(Why is the value subtracted $3$ not $1$?)

$y = 3x^{2} + 6x + 1$
$y = 3\left(x^{2} + 2x\right) + 1$

$y = 3\left(x^{2} + 2x + 1\right) + 1 − 3$

$y = 3\left(x + 1\right)^{2} − 2$