Question 1202758
main coefficient  negative three, so since is function of x, parabola with a maximum, vertical symmetry axis, ....
Vertex at  (0,5).
Range is the real numbers less than or equal to 5.


{{{f(x)=-3x^2+5}}}
{{{graph(400,400,-10,10,-10,10,-3x^2+5)}}}



Two different inverses.
{{{-3y^2+5=x}}}
{{{-3y^2=x-5}}}
{{{y^2=-(x-5)/3}}}
{{{y^2=(5-x)/3}}}
{{{y=0+- sqrt((5-x)/3)}}}

.
.
.

{{{graph(400,400,-10,10,-10,10,-sqrt((5-x)/3))}}}


OR


{{{graph(400,400,-10,10,-10,10,sqrt((5-x)/3))}}}

and identifying domains and ranges to each should be clear.