Respuesta :
Answer with explanation:
⇒Domain:
f(x)= -x² -2 x +15
= - (x²+2 x -15)
Splitting the middle term
= - (x²+5 x - 3 x -15)
= -[ x × (x+5) -3× (x+5)]
= -(x-3)(x+5)
y=f(x)=(3 -x)(x+5)
Domain of the function is defined as set of all values of x, for which y is defined.
f(x) is defined as all real values of x.So, Domain = R.
⇒Range:
[tex]y=-x^2-2 x +15\\\\y=-(x^2+2 x-15)\\\\ y=-[(x+1)^2-1-15]\\\\y= -(x+1)^2+16\\\\ 16 -y=(x+1)^2\\\\x+1=\pm\sqrt{16-y}\\\\x=\pm\sqrt{16-y}-1[/tex]
Range of the function is defined as set of all values of y, for which x is defined.
⇒16 -y ≥ 0
⇒y ≤ 16
Option B
The domain is all real numbers. The range is {y|y ≤ 16}.
