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2 years ago

Can you double a square with a straightedge and a compass?

1 answer:

8 0

I'd say yes. If you use the diagonal as a reference. Take the square and set your compass to the width of the diameter of the square. Now put it on the page and mark a point. Put the point of the compass on that mark and make another mark. Now you can connect the two marks with the straight edge and you have a line that, if you made a square with sides that long, it'd have 2x the area of the first one. That's because the diagonal is the square root of 2 larger than one side. Square the square root of 2 and you've got 2. You lust need to make a perpendicular line to the first one to get the box going.

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What is the unit rate for 108 diapers for 25.18 dollars

krek1111 [17]

You have to divide 108 with 25.18

about 4.3/1

4 0

3 years ago

Let X1, . . . ,Xn be an i.i.d. random sample from a N(0, 1) population. Define Y1 = 1 n n X i=1 Xi , Y2 = 1 n n X i=1 |Xi| . Cal

nalin [4]

For each $1\le i\le n$ , $E[X_i]=0$ , so that

$\displaystyle E[Y_1]=E\left[\frac1n\sum_{i=1}^nX_i\right]=\frac1n\sum_{i=1}^nE[X_i]=0$

Meanwhile,

$\displaystyle E[Y_2]=\frac1n\sum_{i=1}^nE[|X_i|]$

Each of the $X_i$ have PDF

$f_{X_i}(x)=\dfrac1{\sqrt{2\pi}}e^{-x^2/2}$

for $x\in\Bbb R$ . From this we get

$E[|X_i|]=\displaystyle\frac1{\sqrt{2\pi}}\int_{-\infty}^\infty|x|e^{-x^2/2}\,\mathrm dx=\sqrt{\frac2\pi}\int_0^\infty xe^{-x^2/2}\,\mathrm dx=\sqrt{\frac2\pi}$

$\implies E[Y_2]=n\sqrt{\dfrac2\pi}$

8 0

2 years ago

Three sodas and four hotdogs costs $15. Two sodas and a hotdog costs $5. How much does seven hotdogs cost?

KengaRu [80]

Answer:

$26.25

Step-by-step explanation:

I'm not completely sure if I did this right because I haven't used this in a while, but let's say sodas are x and hot dogs are y. The first equation would be 3x+4y=15 and in order to solve for x or y you have isolate them to seperate sides because if there is not letter on the other side, it will just end up being zero... if that makes sense. subtract 3x so the equation is now 4y=15-3x and divide everything by 4, to make the equation y=3.75-3/4x. Do the same thing but subracting the 4y and dividing by 3 to get the x value. Now we're left with y=-3/4+3.75 and x=5-4/3y (or x=5-1 1/3y). remember that x=sodas and y=hotdogs. The equation we need to create has seven hot dogs and no sodas, so we simply need to take the equation for y and substitute y for 7 because we have 7 hot dogs and y is the symbol used for hot dogs. This equation would now be 7(-3/4x+3.75) because hotdog=y=-3/4x+3.75, so hotdog=-3/4+3.75 and we have 7 hot dogs so you just multiply that by 7

7 0

2 years ago

Which is the graph of f(x) = 1 (4)X?<br> ity

KIM [24]

Answer:

Its a quadratic function

Step-by-step explanation:The formula concludes to a quadratic function.

5 0

3 years ago

Write a polynomial function with zeros -3,5,8

klemol [59]

Answer:

x^3-10x^2+x+120

Step-by-step explanation:

Assuming you mean roots -3, 5, 8

These happen when we have (x+3)(x-5)(x-8)=0

Expand this

(x^2-2x-15)(x-8)=0

=x^3-2x^2-15x-8x^2+16x+120

=x^3-10x^2+x+120

3 0

2 years ago