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3 years ago

Pleas help me !!! It’s due today

Mathematics

1 answer:

kolezko [41]3 years ago

6 0

KE=0.5xmxv2
=0.5x 1.2x10^3x (3.4x10^3)^2=6936000000

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Use substitution to find the indefinite integral 8x+7/(8x^2+14x)^4

a_sh-v [17]

Hello
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3 years ago

What is 2 x 10 to the -6th power?

White raven [17]

Answer:

2 x 10 to the -6th power is .000002.

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3 years ago

Read 2 more answers

Solve for XX. Assume XX is a 2×22×2 matrix and II denotes the 2×22×2 identity matrix. Do not use decimal numbers in your answer.

sveticcg [70]

The question is incomplete. The complete question is as follows:

Solve for X. Assume X is a 2x2 matrix and I denotes the 2x2 identity matrix. Do not use decimal numbers in your answer. If there are fractions, leave them unevaluated.

$\left[\begin{array}{cc}2&8\\-6&-9\end{array}\right]$ · X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ =I.

First, we have to identify the matrix I. As it was said, the matrix is the identiy matrix, which means

I = $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

So, $\left[\begin{array}{cc}2&8\\-6&-9\end{array}\right]$ · X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

Isolating the X, we have

X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{cc}2&8\\-6&-9\end{array}\right]$ - $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

Resolving:

X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{ccc}2-1&8-0\\-6-0&-9-1\end{array}\right]$

X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{ccc}1&8\\-6&-10\end{array}\right]$

Now, we have a problem similar to A.X=B. To solve it and because we don't divide matrices, we do X=A⁻¹·B. In this case,

X= $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ ⁻¹· $\left[\begin{array}{ccc}1&8\\-6&-10\end{array}\right]$

Now, a matrix with index -1 is called Inverse Matrix and is calculated as: A . A⁻¹ = I.

So,

$\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ · $\left[\begin{array}{ccc}a&b\\c&d\end{array}\right]$ = $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

9a - 3b = 1

7a - 6b = 0

9c - 3d = 0

7c - 6d = 1

Resolving these equations, we have a= $\frac{2}{11}$ ; b= $\frac{7}{33}$ ; c= $\frac{-1}{11}$ and d= $\frac{-3}{11}$ . Substituting:

X= $\left[\begin{array}{ccc}\frac{2}{11} &\frac{-1}{11} \\\frac{7}{33}&\frac{-3}{11} \end{array}\right]$ · $\left[\begin{array}{ccc}1&8\\-6&-10\end{array}\right]$

Multiplying the matrices, we have

X= $\left[\begin{array}{ccc}\frac{8}{11} &\frac{26}{11} \\\frac{39}{11}&\frac{198}{11} \end{array}\right]$

6 0

3 years ago

A shoemaker makes 15,200$ and 912$ in commission (included in 15,200). What is the percent he made in commission to he whole amo

kodGreya [7K]

The total amount of money he only made is calculated by the formula:

amount made = 15,200 – 912

amount made = 14,288

Therefore the percentage commission was:

% commission = 912 / 14,288 * 100%

% commission = 6.38 %

6 0

3 years ago

Which of the following situations could be modeled by an exponential function?

Sauron [17]

Answer: Option D.

Step-by-step explanation:

An exponential function is something like:

f(x) = A*(r)^x

Where:

A = initial amount.

r = rate of growth

x = variable.

This type of function is used to describe situations like "you have A dollars, and it increases by 30% each week"

or:

"There is a population of A animals, and it doubles each year"

Let's analyze briefly all the given options and see which one is an exponential function.

A) The water level of a tank decreases by 5 gallons every day.

This is a linear relation, if W is the initial amount of water, and x is the number of days, then the water level of the tank after x days is:

y = W - 5 gal*x

B) The amount of money collected by a charity increases by $5,000 each year.

The amount collected increases $5000 each year.

Then if in year 1 they collected A.

in year 2 they collected A + $5000

in year 3 they collected A + 2*$5000

We already can see the pattern, this is a linear relation:

in year X they colected A + (X - 1)*$5000

C) A tree was 10 feet tall when purchased and grows at a rate of 2 feet per year.

if y is the height of the tree, and x is the number of years, this can be written as:

y = 10ft + x*2ft

Again, a linear relation.

D) The number of people in a stadium is decreasing at a rate of 45% every 10 minutes.

Let's define x as each "lapse" of 10 minutes that passes.

If N is the initial number of people in te stadium, then after 10 minutes the number of people is = N*(1 - 45%/100%) = N*(1 - 0.45) = N*0.55

After another 10 minutes, the population decreases again.

N*0.55*(1 - 45%/100%) = N*0.55*0.55 = N*0.55^2

We can see the pattern here, this can be written as

People(x) = N*(0.55)^x

This is an exponential function.

3 0

2 years ago