# What is the axis of symmetry of the parabola with the equation x-4=1/4(y+1)^2?

Apr 8, 2018

Axis of symmetry is $y + 1 = 0$

#### Explanation:

If the equation of parabola is of the form $y = a {\left(x - h\right)}^{2} + k$, axis of symmetry is $x - h = 0$ or $x = h$

and if the equation of parabola is of the form $x = a {\left(y - k\right)}^{2} + h$, axis of symmetry is $y - k = 0$ or $y = k$.

We can write $x - 4 = \frac{1}{4} {\left(y + 1\right)}^{2}$ i.e.

$x = \frac{1}{4} {\left(y + 1\right)}^{2} + 4$ and

and axis of symmetry is $y + 1 = 0$