Question

Approximate when the function is positive, negative, increasing, or decreasing.

-x4 + 8x² +9
Ay
y =
-2
20
X
The function is positive:
decreasing:
increasing:
:: -3 and
::x>3
all real numbers
negative:
#
::
and
x < -2 :: 0 -2 and
#x>2
&
I
SO+

Answer 1

Answer: -3<x<3, x<-3, x>3, x<-2, 0<x<2, -2<x<0, x>2

Explanation:

The function is positive when it is above the x-axis.

The function is negative when it is below the x-axis.

The function is increasing when it is going "up".

The function is decreasing when it is going "down".