Answer:
B
Step-by-step explanation:
The vertex is the turning point of the parabola.
First find the zeros by equating y to zero, that is
(x - 6)(x + 12) = 0
Equate each factor to zero and solve for x
x - 6 = 0 ⇒ x = 6
x + 12 = 0 ⇒ x = - 12
The vertex lies on the axis of symmetry which is situated at the midpoint of the zeros, thus
=
=
= - 3
Thus the x- coordinate of the vertex is x = - 3 → B
Answer: The number of rolls of paper is .
Step-by-step explanation: Given that Andy is hanging wallpaper in his kitchen. 6 rolls of wallpaper is used to cover of the walls.
We are to find the number of rolls of paper used per wall.
We will be using unitary method to solve the given problem.
We have,
Now, number of rolls used to cover of the walls = 6.
Therefore, number of rolls used to cover 1 wall is given by
Thus, rolls of paper used per wall.
Answer: a. n= 1068
b. n= 164
Step-by-step explanation:
The formula to find the sample size :
, where p=prior population proportion , z* = critical z-value and E = Margin of error.
Here , let p=proportion of computers that use a new operating system.
Given : Confidence level = 95%
i.e. z* = 1.96 [by z-table]
Margin of error : E = 3% =0.03
a. If p is unknown , then we assume p=0.5
Then,
i.e. n= 1068
b. p=0.96
Then,
i.e. n= 164.
notice that, if Q is the midpoint of PR, that simply means that PQ = QR = 43.