Question 7619
quadratic factorises to {{{y = (4-x)(4+x)}}}


so, {{{(4-x)(4+x) = 0}}}


so the roots are either x=4 or x=-4. 


As the curve has - x-squared term, it is a n-shape, whose maximum will be at the x-values mid-way between its roots, ie at x=0.


When x=0, y is 16.


So, domain is xeR
range is yeR, y<=16


jon.