# What is the standard form of y= (x - 8) (4x+1) ?

Mar 3, 2016

The quadratic form is y = $4 {x}^{2} - 31 x - 8$.
If it is for making a graph, the standard form is
${\left(x - \frac{31}{8}\right)}^{2} = 4 \left(\frac{1}{16}\right) \left(y + \frac{993}{16}\right)$.

#### Explanation:

The equation represents the parabola with .
Vertex: $\left(\frac{31}{8} , - \frac{993}{16}\right)$,
Axis: Parallel to +ve y-axis,
Focus at $\left(\frac{31}{8} , - \frac{993}{16} + \frac{1}{16}\right)$ and
Directrix along x = $\left(\frac{31}{8} , - \frac{993}{16} - \frac{1}{16}\right)$.