Answer:
y = -2(x + 1)^2 + 8
Step-by-step explanation:
The equation of a parabola can be written in the form;
y = a(x-h)^2 + k
where a is the multiplier (h,k) is the vertex
so h = -1 and k = 8
Plug in these values
y = a(x + 1)^2 + 8
So to get the value of a, we use the point where the parabola passes through which is the point (1,0)
Simply substitute the values of x and y
0 = a(1 + 1)^2 + 8
0 = a(2)^2 + 8
-8 = 4a
a = -8/4
a = -2
So therefore the equation of the parabola is ;
y = -2(x + 1)^2 + 8
Answer:
a) Var[z] = 1600
D[z] = 40
b) Var[z] = 2304
D[z] = 48
c) Var[z] = 80
D[z] = 8.94
d) Var[z] = 80
D[z] = 8.94
e) Var[z] = 320
D[z] = 17.88
Step-by-step explanation:
In general
V([x+y] = V[x] + V[y] +2Cov[xy]
how in this problem Cov[XY] = 0, then
V[x+y] = V[x] + V[y]
Also we must use this properti of the variance
V[ax+b] = 
V[x]
and remember that
standard desviation = ![\sqrt{Var[x]}](https://tex.z-dn.net/?f=%5Csqrt%7BVar%5Bx%5D%7D)
a) z = 35-10x
Var[z] = 
Var[x] = 100*16 = 1600
D[z] = 
= 40
b) z = 12x -5
Var[z] = 
Var[x] = 144*16 = 2304
D[z] = 
= 48
c) z = x + y
Var[z] = Var[x+y] = Var[x] + Var[y] = 16 + 64 = 80
D[z] = 
= 8.94
d) z = x - y
Var[z] = Var[x-y] = Var[x] + Var[y] = 16 + 64 = 80
D[z] = = 8.94
e) z = -2x + 2y
Var[z] = 4Var[x] + 4Var[y] = 4*16 + 4*64 = 320
D[z] = 
= 17.88
Answer:c=b^a
Step-by-step explanation:
Logb c=a
In exponential form
c=b^a
Answer:
The other angle is 190-7x.
Step-by-step explanation:
Angles in a triangle add up to 180 degrees.
Let A be the third angle.
A + (3x-20) + (4x+10) = 180
A = 180 - (3x - 20) - (4x + 10) = 190 - 7x
Answer:
72
Step-by-step explanation:
x in (-oo:+oo)
(x/4)/3 = 6 // - 6
(x/4)/3-6 = 0
1/12*x-6 = 0 // + 6
1/12*x = 6 // : 1/12
x = 6/1/12
x = 72
x = 72
