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3 years ago

A FAMILY HAS 2 CHILDREN. FIND THE PROBABILITY THAT BOTH ARE BOYS IF IT IS KNOWN THAT

1 answer:

3 0

1/2 because if there's at least 1 boy that same boy could be the elder child so 1 could be a boy and the other a girl younger than him

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HELP! WILL GIVE BRAINLIEST!

romanna [79]

Answer:

I Know it is B trust me

Step-by-step explanation:

8 0

2 years ago

Read 2 more answers

Consider the sequence whose first five terms are shown. -59 ,-67 ,-65 ,-53 ,-31 ,... The first term is ____ To calculate the sec

GaryK [48]

Step-by-step explanation:

The sequence is as follows :

-59 ,-67 ,-65 ,-53 ,-31 ,...

The first term = -59

The second term = -67

Common difference = second term - first term

$=-67-(-59)\\\\=-8$

To calculate the second term add (-8).

To calculate each additional term, increase the amount added by -8.

7 0

2 years ago

The circumference of a standard baseball is about 9in. About how many square inches of horsehide are required to cover 100 balls

Marta_Voda [28]

This is the concept of area of solid materials, we are required to calculate the total area of horsehide that is required to cover 100 balls with each having a circumference of 9 in.
The area of hide required will be given by:
area=(area of each ball)*(total number of balls)
area of each ball is given by:
SA=4πr^2
given that the circumference is 9in, we are required to find the radius of the ball
Circumference, c=2πr
thus;
9=2πr
r=9/(2π)
r=1.4 in
Therefore the surface area will be:
SA=4π*1.4^2=24.6 in^2
Therefore the area of horsehide required to cover 100 balls will be:
Area=24.6*100=2,460 in^2.

5 0

2 years ago

(x^2y+e^x)dx-x^2dy=0

klio [65]

It looks like the differential equation is

$\left(x^2y + e^x\right) \,\mathrm dx - x^2\,\mathrm dy = 0$

Check for exactness:

$\dfrac{\partial\left(x^2y+e^x\right)}{\partial y} = x^2 \\\\ \dfrac{\partial\left(-x^2\right)}{\partial x} = -2x$

As is, the DE is not exact, so let's try to find an integrating factor µ(x, y) such that

$\mu\left(x^2y + e^x\right) \,\mathrm dx - \mu x^2\,\mathrm dy = 0$

*is* exact. If this modified DE is exact, then

$\dfrac{\partial\left(\mu\left(x^2y+e^x\right)\right)}{\partial y} = \dfrac{\partial\left(-\mu x^2\right)}{\partial x}$

We have

$\dfrac{\partial\left(\mu\left(x^2y+e^x\right)\right)}{\partial y} = \left(x^2y+e^x\right)\dfrac{\partial\mu}{\partial y} + x^2\mu \\\\ \dfrac{\partial\left(-\mu x^2\right)}{\partial x} = -x^2\dfrac{\partial\mu}{\partial x} - 2x\mu \\\\ \implies \left(x^2y+e^x\right)\dfrac{\partial\mu}{\partial y} + x^2\mu = -x^2\dfrac{\partial\mu}{\partial x} - 2x\mu$

Notice that if we let µ(x, y) = µ(x) be independent of y, then ∂µ/∂y = 0 and we can solve for µ :

$x^2\mu = -x^2\dfrac{\mathrm d\mu}{\mathrm dx} - 2x\mu \\\\ (x^2+2x)\mu = -x^2\dfrac{\mathrm d\mu}{\mathrm dx} \\\\ \dfrac{\mathrm d\mu}{\mu} = -\dfrac{x^2+2x}{x^2}\,\mathrm dx \\\\ \dfrac{\mathrm d\mu}{\mu} = \left(-1-\dfrac2x\right)\,\mathrm dx \\\\ \implies \ln|\mu| = -x - 2\ln|x| \\\\ \implies \mu = e^{-x-2\ln|x|} = \dfrac{e^{-x}}{x^2}$

The modified DE,

$\left(e^{-x}y + \dfrac1{x^2}\right) \,\mathrm dx - e^{-x}\,\mathrm dy = 0$

is now exact:

$\dfrac{\partial\left(e^{-x}y+\frac1{x^2}\right)}{\partial y} = e^{-x} \\\\ \dfrac{\partial\left(-e^{-x}\right)}{\partial x} = e^{-x}$

So we look for a solution of the form F(x, y) = C. This solution is such that

$\dfrac{\partial F}{\partial x} = e^{-x}y + \dfrac1{x^2} \\\\ \dfrac{\partial F}{\partial y} = e^{-x}$

Integrate both sides of the first condition with respect to x :

$F(x,y) = -e^{-x}y - \dfrac1x + g(y)$

Differentiate both sides of this with respect to y :

$\dfrac{\partial F}{\partial y} = -e^{-x}+\dfrac{\mathrm dg}{\mathrm dy} = e^{-x} \\\\ \implies \dfrac{\mathrm dg}{\mathrm dy} = 0 \implies g(y) = C$

Then the general solution to the DE is

$F(x,y) = \boxed{-e^{-x}y-\dfrac1x = C}$

5 0

2 years ago

What is the value of x

Goshia [24]

Sum of all adjacent angles is 180°.

3x + 12 + x = 180
4x + 12 = 180
4x = 168
x = 42°

-----------------------------------------
Answer: x = 42°
-----------------------------------------

3 0

2 years ago