# How do you write the equation of the parabola in vertex form given vertex of a parabola is (-3,7) and the y-intercept is 0?

Jul 26, 2016

y = -7/9(x + 3)^2 + 7

#### Explanation:

The general vertex form is
$y = a {\left(x + 3\right)}^{2} + 7$
Find a.
y-intercept = 0 when x = 0, then,
$0 = a {\left(0 + 3\right)}^{2} + 7$ --> 9a + 7 = 0 --> a = - 7/9
Vertex form of y:
$y = - \frac{7}{9} {\left(x + 3\right)}^{2} + 7$