Question 332530
Find the roots.
{{{x^2-16<= 0}}}
{{{(x-4)(x+4)<=0}}}
root at x = 4 and x = -4

Now pick a value less than -4. let's say -10.
When x=-10, then {{{100-16 = 84}}} which is > 0
Pick a value between the two root. Say x=0
When x=0 {{{0-16= -16}}} which is < 0
Pick a value greater than 4, say 10
Again {{{100-16= 84}}} which is greater than 0.
So points to the left of -4 and to the right of 4 do not satisfy the inequality.
The plot will be all points above the curve x^2-16 and below the x axis, between -4 and 4
See this URL for a plot
http://www.wolframalpha.com/input/?i=x^2-16%3C%3D0