Positive 28 because to negative will equal a positive number
Answer:
Domain is all real numbers or (negative infinity, positive infinity)
Step-by-step explanation:
Domain is all values of <em>x</em> (inputs) that will work with the function. Since a parabola has no limits for <em>x</em>, and all numbers work for <em>x</em>, then the domain can be any number. That leaves us with All Real Numbers as our answer.
Answer:
Mean = 1.42
Variance = 0.58
Step-by-step explanation:
Given: X denote the number of luxury cars sold in a given day, and Y denote the number of extended warranties sold.
Also, joint probability function of X and Y are given.
To find:
mean and variance of X
Solution:
From the given joint probability function of X and Y,
![P(X=0)=\frac{1}{6}\\P(X=1)=\frac{1}{12}+\frac{1}{6}=\frac{1+2}{12}=\frac{3}{12}\\P(X=2)=\frac{1}{12}+\frac{1}{3}+\frac{1}{6}=\frac{1+4+2}{12}=\frac{7}{12}](https://tex.z-dn.net/?f=P%28X%3D0%29%3D%5Cfrac%7B1%7D%7B6%7D%5C%5CP%28X%3D1%29%3D%5Cfrac%7B1%7D%7B12%7D%2B%5Cfrac%7B1%7D%7B6%7D%3D%5Cfrac%7B1%2B2%7D%7B12%7D%3D%5Cfrac%7B3%7D%7B12%7D%5C%5CP%28X%3D2%29%3D%5Cfrac%7B1%7D%7B12%7D%2B%5Cfrac%7B1%7D%7B3%7D%2B%5Cfrac%7B1%7D%7B6%7D%3D%5Cfrac%7B1%2B4%2B2%7D%7B12%7D%3D%5Cfrac%7B7%7D%7B12%7D)
Mean of X:
![E(X)=\sum XP(X)\\=0\left ( \frac{1}{6} \right )+1\left ( \frac{3}{12} \right )+2\left ( \frac{7}{12} \right )\\=0+\frac{3}{12}+\frac{14}{12}\\=\frac{17}{12}=1.42](https://tex.z-dn.net/?f=E%28X%29%3D%5Csum%20XP%28X%29%5C%5C%3D0%5Cleft%20%28%20%5Cfrac%7B1%7D%7B6%7D%20%5Cright%20%29%2B1%5Cleft%20%28%20%5Cfrac%7B3%7D%7B12%7D%20%5Cright%20%29%2B2%5Cleft%20%28%20%5Cfrac%7B7%7D%7B12%7D%20%5Cright%20%29%5C%5C%3D0%2B%5Cfrac%7B3%7D%7B12%7D%2B%5Cfrac%7B14%7D%7B12%7D%5C%5C%3D%5Cfrac%7B17%7D%7B12%7D%3D1.42)
Variance of X:
![E(X^2)=\sum X^2P(X)\\=0^2\left ( \frac{1}{6} \right )+1^2\left ( \frac{3}{12} \right )+2^2\left ( \frac{7}{12} \right )\\=0+\frac{3}{12}+\frac{28}{12}\\=\frac{31}{12}](https://tex.z-dn.net/?f=E%28X%5E2%29%3D%5Csum%20X%5E2P%28X%29%5C%5C%3D0%5E2%5Cleft%20%28%20%5Cfrac%7B1%7D%7B6%7D%20%5Cright%20%29%2B1%5E2%5Cleft%20%28%20%5Cfrac%7B3%7D%7B12%7D%20%5Cright%20%29%2B2%5E2%5Cleft%20%28%20%5Cfrac%7B7%7D%7B12%7D%20%5Cright%20%29%5C%5C%3D0%2B%5Cfrac%7B3%7D%7B12%7D%2B%5Cfrac%7B28%7D%7B12%7D%5C%5C%3D%5Cfrac%7B31%7D%7B12%7D)
![var(X)=E\left [ X^2 \right ]-\left ( E\left [ X \right ] \right )^2\\=\frac{31}{12}-\left ( \frac{17}{12} \right )^2\\=\frac{31}{12}-\frac{289}{144}\\=\frac{372-289}{144}\\=\frac{83}{144}\\=0.58](https://tex.z-dn.net/?f=var%28X%29%3DE%5Cleft%20%5B%20X%5E2%20%5Cright%20%5D-%5Cleft%20%28%20E%5Cleft%20%5B%20X%20%5Cright%20%5D%20%5Cright%20%29%5E2%5C%5C%3D%5Cfrac%7B31%7D%7B12%7D-%5Cleft%20%28%20%5Cfrac%7B17%7D%7B12%7D%20%5Cright%20%29%5E2%5C%5C%3D%5Cfrac%7B31%7D%7B12%7D-%5Cfrac%7B289%7D%7B144%7D%5C%5C%3D%5Cfrac%7B372-289%7D%7B144%7D%5C%5C%3D%5Cfrac%7B83%7D%7B144%7D%5C%5C%3D0.58)
Answer:
B
Step-by-step explanation:
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r is the radius
To obtain this form use the method of completing the square
Given
x² - 8x + y² - 2y - 8 = 0 ( add 8 to both sides )
x² - 8x + y² - 2y = 8
add ( half the coefficient of the x/y terms )² to both sides
x² + 2(- 4)x + 16 + y² + 2(- 1)y + 1 = 8 + 16 + 1
(x - 4)² + (y - 1)² = 25 → B
Answer:
That is enough information to determine that the shape is a parallelogram.
Step-by-step explanation: