9514 1404 393
Answer:
D) x and ( y z + 1 2 ) are independent of each other
Step-by-step explanation:
Assuming this is not intended to be describing a function named x with an argument of yz+12, the variables in any expression are assumed to be independent of each other, unless additional information is provided showing their dependencies.
Here, there is no such additional information, so we must assume ...
x and (yz +12) are independent of each other
_____
<em>Additional comment</em>
The assumption stated in the answer is intended to ensure we're not concerned with something of the form ...
g(x)
which is an expression saying 'g' is dependent on 'x'. If we know 'g' is a function name, then g(yz+12) will make 'g' be dependent on (yz+12).
Similarly, if x(a) is intended to mean that x is a function of 'a', then the corresponding x(yz+12) will mean that x is dependent on (yz+12). This would be quite unusual, since letters toward the end of the alphabet are usually used for variable names, while letters in the middle of the alphabet are used for function names.

Substitute this into the parabolic equation,

We're told the line
intersects
twice, which means the quadratic above has two distinct real solutions. Its discriminant must then be positive, so we know

We can tell from the quadratic equation that
has its vertex at the point (3, 6). Also, note that

and

so the furthest to the right that
extends is the point (5, 2). The line
passes through this point for
. For any value of
, the line
passes through
either only once, or not at all.
So
; in set notation,

93.96. You multiply them together to get the answer.
No, a closed circle does include that number.
Closed circles are used for greater than or equal to or less than or equal to
Open circles are only used for greater than or less than