Find the area of a circle with a radius of 3

Mathematics

2 answers:

ExtremeBDS [4]3 years ago

7 0

Answer: 28.27

Step-by-step explanation: first multiply the radius by itself 3 times 3 = 9

then take 9 and multiply it by 3.14 which is 28.27

hope this helps mark me brainliest

Aleks04 [339]3 years ago

3 0

Step-by-step explanation:

So to find the area of a circle, you have to use this formula:

A = 3.14r^2

So just plug everything in like this:

A = 3.14 * 3^2

Then solve

A = 3.14 * 9

Answer:

Area is = 28.26 units^2

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Apply Crammer's Rule to find the solution to the following quations .2x + 3y = 1, 3x + y = 5

Bond [772]

Answer:

The solution to the equation system given is:

<u>x = 2</u>
<u>y = -1</u>

Step-by-step explanation:

First, we must know the equations given:

2x + 3y = 1
3x + y = 5

Following Crammer's Rule, we have the matrix form:

$\left[\begin{array}{ccc}2&3\\3&1\end{array}\right] =\left[\begin{array}{ccc}x\\y\end{array}\right] = \left[\begin{array}{ccc}1\\5\end{array}\right]$

Now we solve using the determinants:

$x=\frac{\left[\begin{array}{ccc}1&3\\5&1\end{array}\right]}{\left[\begin{array}{ccc}2&3\\3&1\end{array}\right] } =\frac{(1*1)-(5*3)}{(2*1)-(3*3)} = \frac{1-15}{2-9} =\frac{-14}{-7} = 2$

$y=\frac{\left[\begin{array}{ccc}2&1\\3&5\end{array}\right]}{\left[\begin{array}{ccc}2&3\\3&1\end{array}\right] } =\frac{(2*5)-(3*1)}{(2*1)-(3*3)}=\frac{10-3}{2-9} =\frac{7}{-7}=-1$

Now, we can find the answer which is x= 2 and y= -1, we can replace these values in the equation to confirm the results are right, with the first equation:

2x + 3y = 1
2(2) + 3(-1)= 1
4 - 3 = 1
1 = 1

And, with the second equation:

3x + y = 5
3(2) + (-1) = 5
6 - 1 = 5
5 = 5

4 0

3 years ago

Write the explicit formula

Margaret [11]

Answer:

Step-by-step explanation:

Since there is no single number we can add to one number in the sequence to get to the next one, this is not arithmetic. That means it's geometric, if it's a sequence at all. To get from 2 to 6 we multiply by 3. To get from 6 to 18 we multiply by 3. To get from 18 to 54 we multiply by 3. Therefore, this is in fact geometric and the common ratio is 3. The standard form of a geometric explicit formula is

$A_n=a_1(r)^{n-1$ where n is the position of a number in the sequence, a1 is the first number in the sequence, and r is the common ratio. We have then

a1 = 2 and r = 3. Therefore, the explicit formula is

$A_n=2(3)^{n-1$ and you can use this to find the value of any number in the sequence. Very handy; much more so than the recursive formula, which requires that all the numbers in a sequence be found in order in order to get to a desired value.