(Because (x- 1)? ≥0)

Function y = (1/2) (x? -2x-3)

middle

Let t=x? -2x-3

rule

t≥-4,y=( 1/2)^t

And the function y = (1/2) t is a monotonically decreasing function.

So y = (1/2) t ≤ (1/2)-4.

= 16

y = ( 1/2) t > 0

So the range is (0, 16)