# How do you find the axis of symmetry, and the maximum or minimum value of the function y=x^2 - 3?

Apr 2, 2018

Maximum value is $\left(0 , - 3\right)$
And axis of symmetry is the y axis.

#### Explanation:

Comparing with $y = a {x}^{2} + b x + c$
$a = 1$
$b = 0$
$c = - 3$

Axis of symmetry of a parabola is $x = {x}_{\max}$

So,
${x}_{\max} = - \frac{b}{2 a}$
=0/(2×1)
$= 0$
Hence axis of symmetry is $x = 0$
Evaluate $x = 0$ to get maximum.
Thank you