<h3>
Answer: Choice B</h3>
The set notation includes all values from -5 to 0, but the domain only includes the integer values
eg: something like -1.2 is in the second set, but it is not in the set {-5,-4,-3,-2,-1}
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Further explanation:
Let's go through the answer choices one by one
- A. This is false because 0 does not come before -5, but instead -5 is listed first. The order -5,-4,-3,-2,-1,0 is correct meaning that
is the correct order as well. - B. This is true. A value like x = -1.2 is in the set
since -1.2 is between -5 and 0; but -1.2 is not in the set {-5, -4, -3, -2, -1, 0}. So the distinction is that we're either considering integers only or all real numbers in this interval. To ensure that we only look at integers, the student would have to write
. The portion
means "x is in the set of integers". The Z refers to the German word Zahlen, which translates to "numbers". - C. This is false. The student used the correct inequality signs to indicate x is -5 or larger and also 0 or smaller; basically x is between -5 and 0 inclusive of both endpoints. The "or equal to" portions indicate we are keeping the endpoints and not excluding them.
- D. This is false. Writing
would not make any sense. This is because that compound inequality breaks down into
. Try to think of a number that is both smaller than -5 AND also larger than 0. It can't be done. No such number exists.
Answer:
45 km/h
Step-by-step explanation:
In the first part of the trip, he already covered 30 km so we can subtract that from the total distance
45 - 30 = 15
This means he has 15 km to go
He also took an hour, or 60 minutes, to get to school. We subtract the time spent of the first part and time spent talking to a friend from the 60 minutes
60 - 35 = 25
25 - 5 = 20
He took 20 minutes to cover the second part of the journey
Speed = distance/time
15/20 = 0.75
He covered 0.75 km per MINUTE
to find it in km/h, we just multiply the number by 60
0.75 x 60 = 45
Think of the greater than sign as an equals sign. Then, you solve for m
Answer:
659.6 ft
Step-by-step explanation:
x = 140 / tan 23
x = 329.82(rounded to hundredth)
so total ground distance between the cables = 2x = 2(329.82) = 659.64 feet
Answer:
One possible equation is
, which is equivalent to
.
Step-by-step explanation:
The factor theorem states that if
(where
is a constant) is a root of a function,
would be a factor of that function.
The question states that
and
are
-intercepts of this function. In other words,
and
would both set the value of this quadratic function to
. Thus,
and
would be two roots of this function.
By the factor theorem,
and
would be two factors of this function.
Because the function in this question is quadratic,
and
would be the only two factors of this function. In other words, for some constant
(
):
.
Simplify to obtain:
.
Expand this expression to obtain:
.
(Quadratic functions are polynomials of degree two. If this function has any factor other than
and
, expanding the expression would give a polynomial of degree at least three- not quadratic.)
Every non-zero value of
corresponds to a distinct quadratic function with
-intercepts
and
. For example, with
:
, or equivalently,
.