Answer:
27.75m 2
Step-by-step explanation:
Answer:
9.364 is the expected number of points.
we can approximate this to 10 points if we want a whole number
Step-by-step explanation:
We have these variables:
[0,5,10,15]
P(x= 0) = p(y>20)+p(y<-20) = 2p(y>20)
P(x=5) = p(-20<=y<=10)+p(10<=y<=20) = 2p(10<=y<=20)
P(x=10) = p(-10<=y<=-3)+p(3<=y<=10) = 2p(3<=y<=10)
P(x=15) = p(-3<=y<=3) = 2p(0<=y<=3)
Z = y/10
Therefore
P(x= 0) = 2(y>20)
= 2p(z>2) = 2(1-p<=2)
= 2(1-0.9772)
= 0.0456
P(x= 5)
= 2p(10<=y<=20)
= 2p(1<=z<=2)
= 2(0.9772-0.8413)
= 0.2718
P(x= 10)
= 2p(3<=y<=10)
= 2p(0.3<=z<=1)
= 2(0.8413-0.6179)
= 0.4468
P(x = 15)
= P(0.6179-0.3821)
= 0.2358
To get expected value of Y
0(0.0456)+5(0.2718)+10(0.4468)+15(0.2358)
= 1.359 + 4.468 + 3.537
= 9.364
E[Y] = 9.364
The system of equation that will represent her situation is as follows:
1.39b + 2.49m = 50.73
1.29b + 2.69m = 51.63
<h3>How to represent system of equation?</h3>
At store A she will pay a total sum of $50.73 for bread and milk.
At store B she will pay a total sum of $51.63 for bread and milk.
Therefore, the system of equation that will represent her situation is as follows:
where
Therefore,
1.39b + 2.49m = 50.73
1.29b + 2.69m = 51.63
learn more on equation here: brainly.com/question/21620502
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Solve cos(4x)-cos(2x)=0 ∀ 0<=x<=2pi ..............(0)
Normal solution:
1. use the double angle formula to decompose, and recall cos^2(x)+sin^2(x)=1
cos(4x)=cos^2(2x)-sin^2(2x)=2cos^2(2x)-1 .................(1)
2. substitute (1) in (0)
2cos^2(2x)-1-cos(2x)=0
3. substitute u=cos(2x)
2u^2-u-1=0
4. Solve for x
factor
(u-1)(u+1/2)=0
=> u=1 or u=-1/2
However, since cos(x) is an even function, so solutions to
{cos(2x)=1, cos(-2x)=1, cos(2x)=-1/2 and cos(-2x)} ...........(2)
are all solutions.
5. The cosine function is symmetrical about pi, therefore
cos(-2x)=cos(2*pi-2x),
solution (2) above becomes
{cos(2x)=1, cos(2pi-2x)=1, cos(2x)=-1/2, cos(2pi-2x)=-1/2}
6. Solve each case
cos(2x)=1 => x=0
cos(2pi-2x)=1 => cos(2pi-0)=1 => x=pi
cos(2x)=-1/2 => 2x=2pi/3 or 2x=4pi/3 => x=pi/3 or 2pi/3
cos(2pi-2x)=-1/2 => 2pi-2x=2pi/3 or 2pi-2x=4pi/3 => x=2pi/3 or x=4pi/3
Summing up,
x={0,pi/3, 2pi/3, pi, 4pi/3}
Answer:
8.57
Step-by-step explanation:
y=AC
7/15=11/y
y=23.57
x=y-15
x=8.57
