Question 252902
your equation is y = 4*sqrt(x).


the graph of that equation looks like this:


{{{graph(1200,600,-1,1,-5,5,4*sqrt(x)))}}}


this equation is valid for all values of x >= 0.


the equation has one root at x = 0 because when x = 0, y = sqrt(0) = 0.


there are no values for y at x = -4 because the domain of this equation is all value of x >= 0.  x = -4 is outside of the domain therefore the range is undefined for that value of x.