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lara31 [8.8K]
3 years ago
14

Read this E[2X^2 â€" Y].

Mathematics
1 answer:
djyliett [7]3 years ago
6 0

Looks like a badly encoded/decoded symbol. It's supposed to be a minus sign, so you're asked to find the expectation of 2<em>X </em>² - <em>Y</em>.

If you don't know how <em>X</em> or <em>Y</em> are distributed, but you know E[<em>X</em> ²] and E[<em>Y</em>], then it's as simple as distributing the expectation over the sum:

E[2<em>X </em>² - <em>Y</em>] = 2 E[<em>X </em>²] - E[<em>Y</em>]

Or, if you're given the expectation and variance of <em>X</em>, you have

Var[<em>X</em>] = E[<em>X</em> ²] - E[<em>X</em>]²

→   E[2<em>X </em>² - <em>Y</em>] = 2 (Var[<em>X</em>] + E[<em>X</em>]²) - E[<em>Y</em>]

Otherwise, you may be given the density function, or joint density, in which case you can determine the expectations by computing an integral or sum.

You might be interested in
given that A=43 degrees , B=82 degrees and c=28, solve triangle ABC. Round to the nearest hundredth. A) C= 93 degrees , b= 33.8
n200080 [17]
A=43°
B=82°
c=28

1) A+B+C=180°
Replacing A=43° and B=82° in the equation above:
43°+82°+C=180°
125°+C=180°
Solving for C. Subtracting 125° both sides of the equation:
125°+C-125°=180°-125°
C=55° (option B or C)

2) Law of sines
a/sin A=b/sin B=c/sin C
Replacing A=43°, B=82°, C=55°, and c=28 in the equation above:
a/sin 43°=b/sin 82°=28/sin 55°

2.1) a/sin 43°=28/sin 55°
Solving for a. Multiplying both sides of the equation by sin 43°:
sin 43°(a/sin 43°)=sin 43°(28/sin 55°)
a=28 sin 43° / sin 55°
Using the calculator: sin 43°=0.681998360, sin 55°=0.819152044
a=28(0.681998360)/0.819152044
a=23.31185549
Rounded to one decimal place
a=23.3

 2.2) b/sin 82°=28/sin 55°
Solving for a. Multiplying both sides of the equation by sin 82°:
sin 82°(b/sin 82°)=sin 82°(28/sin 55°)
b=28 sin 82° / sin 55°
Using the calculator: sin 82°=0.990268069, sin 55°=0.819152044
b=28(0.990268069)/0.819152044
b=33.84903466
Rounded to one decimal place
b=33.8

Answer: Option B) C=55°, b=33.8, a=23.3
8 0
3 years ago
URGENT!!!! What is the distance from (−2, 4) to (0, −6)? Round your answer to the nearest hundredth. 9.23 units 10.20 units 10.9
serg [7]
The distance between two points knowing theirs coordinates:

AB =√[(x₂-x₁)² +(y₂-y₁)²]; ===>A(-2,4) & B(0,-6) Given
                                              A(x₁,y₁) & B(y₂,y₁)

AB =√[(0-(-2))²+(-6-4)²] =√(104) = 10.198 ≈ 10.2
8 0
3 years ago
Read 2 more answers
I- Please someone help me -_- I hate math so much
zzz [600]

Answer:

5 & 13

Step-by-step explanation:

a. -9 + 4 = -5

Absolute Value = 5

b. Absolute value of -9 is 9

9 + 4 = 13

<em>hope this helps :)</em>

6 0
2 years ago
Read 2 more answers
I WILL AWARD BRAINLIST PLS SOLVE
Ivanshal [37]

Answer:

Ah yes rsm.

Anyways, AB is parallel to DE so 72= angle BDE. So BDE+2x+2x=180

72+4x=180

108=4x

x=27

3 0
3 years ago
Mr. Juarez opened a savings account with an initial deposit of $560 and will not make any additional deposits or withdrawals. Th
olga_2 [115]

Answer:

$576.80

Step-by-step explanation:

We have been given that Mr. Juárez opened a savings account with an initial deposit of $560 and will not make any additional deposits or withdrawals. The account earns 1% simple interest.

We are asked to find the total amount that Mr. Juárez will have in his account at the end of 3 years.

We will use simple interest formula to solve our given problem.

A=P (1+rt)

A = Final amount after t years,

P = Principal amount,

r = Annual interest rate in decimal form,

t = Time in years.

Let us convert 1% into decimal form,

1%=1/100=0.01

P=$560 and t=3

A=$560 (1+0.01(3))

A=$560 (1+0.03)

A= $560 (1.03)

A= $576.80

Therefore, Mr. Juárez will have $576. 80 in his account at the end of 3 years. Hope this helps!

5 0
3 years ago
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