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.
The answer would be -2
(4-10)-(8 ÷(-2))
(-6)-(-4)
-6+4
-2
Answer:
See Explanation Below
Step-by-step explanation:
The question is incomplete (because the figure to calculate the perimeter is missing).
However from the comment attached to your question, I understand that the figure looks like a plus sign.
The perimeter of a plane shape is calculated by adding the length of each side of the shape.
Take for instance;
A square of length 5cm.
We know that a square has 4 equal sides; meaning that the length of the other sides are also 5cm
So, the perimeter of the square will be calculated as 5cm + 5cm + 5cm + 5cm = 20cm
Similarly, the perimeter of a triangle whose sides are 4ft, 3ft and 5ft will be calculated by adding up the length of the three sides.
Perimeter of the triangle = 4ft + 3ft + 5ft
Perimeter = 12ft.
Having explained how the perimeter of a plane shape is calculated; take for example, the attachment below.
(The sides are measured in centimetres)
The plus sign has 12 sides; Its perimeter is calculated by adding up the length of the 12 sides.
Perimeter = 3 + 7 + 7 + 5 + 5 + 5 + 5 + 2 + 2 + 4 + 4 + 3
Perimeter = 52cm