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If 2(a^2+b^2)=(a+b)^2 then, <br> >a+b=0,<br> >ab=0,<br> >a=b,<br> >2a=b

Tasya [4]

Answer:

2·(a^2 + b^2) = (a + b)^2

2·a^2 + 2·b^2 = a^2 + 2·a·b + b^2

a^2 + b^2 = 2·a·b

a^2 - 2·a·b + b^2 = 0

(a - b)^2 = 0

a = b

7 0

3 years ago

What is the formula for the expected number of successes in a binomial experiment with n trials and probability of success p? C

charle [14.2K]

Answer:

$(D)E[ X ] =np.$

Step-by-step explanation:

Given a binomial experiment with n trials and probability of success p,

$f(x)=\left(\begin{array}{c}n\\k\end{array}\right)p^x(1-p)^{n-x}, 0\leq x\leq n$

$E(X)=\sum_{x=0}^{n}xf(x)= \sum_{x=0}^{n}x\left(\begin{array}{c}n\\k\end{array}\right)p^x(1-p)^{n-x}$

Since each term of the summation is multiplied by x, the value of the term corresponding to x = 0 will be 0. Therefore the expected value becomes:

$E(X)=\sum_{x=1}^{n}x\left(\begin{array}{c}n\\x\end{array}\right)p^x(1-p)^{n-x}$

Now,

$x\left(\begin{array}{c}n\\x\end{array}\right)= \frac{xn!}{x!(n-x)!}=\frac{n!}{(x-)!(n-x)!}=\frac{n(n-1)!}{(x-1)!((n-1)-(x-1))!}=n\left(\begin{array}{c}n-1\\x-1\end{array}\right)$

Substituting,

$E(X)=\sum_{x=1}^{n}n\left(\begin{array}{c}n-1\\x-1\end{array}\right)p^x(1-p)^{n-x}$

Factoring out the n and one p from the above expression:

$E(X)=np\sum_{x=1}^{n}n\left(\begin{array}{c}n-1\\x-1\end{array}\right)p^{x-1}(1-p)^{(n-1)-(x-1)}$

Representing k=x-1 in the above gives us:

$E(X)=np\sum_{k=0}^{n}n\left(\begin{array}{c}n-1\\k\end{array}\right)p^{k}(1-p)^{(n-1)-k}$

This can then be written by the Binomial Formula as:

$E[ X ] = (np) (p +(1 - p))^{n -1 }= np.$

5 0

3 years ago

Find the quotient. (3. 683 × 104) (7. 51 × 1012) What is the solution in scientific notation? 4. 9041 × (-9)10 4. 9041 × 10-9 4.

ollegr [7]

The value of the expressions (3.683 × 10⁴) and (7.51 × 10¹²) in scientific notation is 4.9041 × 10⁻⁹. Then the correct option is B.

<h3>What is division?</h3>

The division means the separation of something into different parts, sharing of something among different people, places, etc.

The expressions are (3.683 × 10⁴) and (7.51 × 10¹²).

We have to divide (3.683 × 10⁴) from (7.51 × 10¹²).

$\dfrac{3.683 * 10^4}{7.51*10^{12}}\\\\0.4904*10^{-8}\\\\4.9041*10^{-9}$

More about the division link is given below.

brainly.com/question/369266

6 0

2 years ago

You need to wrap a present that is in the shape of a rectangle prism. The present has a length of 5 inches, a width of 4.5 inche

Serggg [28]

The surface area is made up of six sides and the area is then just the sum of the areas of the six sides...

A=2xy+2xz+2yz

A=2(xy+xz+yz) in this case:

A=2(5*4.5+5*3.5+4.5*3.5)

A=2(22.5+17.5+15.75)

A=2(55.75)

A=111.5 in^2

3 0

3 years ago

Read 2 more answers

Find the surface area of a cylinder with a diameter of 10 and a height of 45. Use 3.14 for π. Round your answer to the nearest t

Marina CMI [18]

You can easily use online calculators for this.

Steps:
1) Find radius. 45 / 2 = 22.5
2) Substitute values (r) and (h) in the formula for surface area of a cylinder:
SA = 2πr² + 2πrh
3) Solve the formula.

You should end up with 9542.59 units². This answer is using π.
To get the answer with (3.14), do the steps above.

4 0

3 years ago