Question 955092
x-axis symmetry:Replace y with -y is equivalent equation.
y-axis symmetry:Replace x with -x is equivalent equation.
Origin: Both x- and y-axis symmetry.
Pictures help
a.  y = x² + 3 - y-symmetry
{{{ graph( 500, 500, -10, 10, -10, 10, x^2+3) }}}
b.  y = x³ - x - No x or y symmetry
{{{ graph( 500, 500, -10, 10, -10, 10, x^3-x) }}}
c.  y = sqrt(|x|) - y-symmetry          
{{{ graph( 500, 500, -10, 10, -10, 10, sqrt(abs(x))) }}}