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3 years ago

Find the area of the circle that contains the sector described below. Round to the nearest tenth, if necessary.

Mathematics

1 answer:

Elis [28]3 years ago

6 0

Answer:

The area of the circle is 2520 cm²

Step-by-step explanation:

The area of an arc is given by the following formula:

arc area = pi*r²(angle/360)

In this case we have the area and the angle and we want to find r, so we have:

210 = pi*r²*(30/360)

210 = pi*r²*(1/12)

210*12 = pi*r²

pi*r² = 210*12

r² = 2520/pi

r = sqrt(2520/pi)

r = 28.3221

The area of the circle that has this arc is given by:

area = pi*r²

area = pi*(28.3221)² = 2520 cm²

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If the sum of a number and seven is doubled, the result is one less than the number. find the number

lawyer [7]

(n + 7)2 = n - 1
2n +14 = n - 1
2n - n +14 = n - n - 1
n + 14 -14 = -1 - 14
n = -15
(-15 + 7)2 = -15 - 1
(-8)2 = -16
-16 = -16

7 0

3 years ago

Which equations represent the line that is parallel to 3x − 4y = 7 and passes through the point (−4, −2)? Select two options.

Elanso [62]

Answer:

2 and 5

Step-by-step explanation:

The slope-intercept form of a line is y=mx-b where m is slope and b is y-intercept.

The point-slope form of a line is y-y1=m(x-x1) where m is the slope and (x1,y1) is a point on the line.

The standard form a line is ax+by=c.

So anyways parallel lines have the same slope.

So if we are looking for a line parallel to 3x-4y=7 then we need to know the slope of this line so we can find the slope of our parallel line.

3x-4y=7

Goal: Put into slope-intercept form

3x-4y=7

Subtract 3x on both sides:

-4y=-3x+7

Divide both sides by -4:

$y=\frac{-3}{-4}x+\frac{7}{-4}$

Simplify:

$y=\frac{3}{4}x+\frac{-7}{4}$

So the slope of this line is 3/4. So our line that is parallel to this one will have this same slope.

So we know our line should be in the form of $y=\frac{3}{4}x+b$ .

To find b we will use the point that is suppose to be on our new line here which is (x,y)=(-4,-2).

So plugging this in to solve for b now:

$-2=\frac{3}{4}(-4)+b$

$-2=-3+b$

$3-2=b$

$b=1$

so the equation of our line in slope-intercept form is $y=\frac{3}{4}x+1$

So that isn't option 1 because the slope is different. That was the only option that was in slope-intercept form.

The standard form of a line is ax+by=c and we have 2 options that look like that.

So let's rearrange the line that we just found into that form.

$y=\frac{3}{4}x+1$

Clear the fractions because we only want integer coefficients by multiplying both sides by 4.

This gives us:

$4y=3x+4$

Subtract 3x on both sides:

$-3x+4y=4$

I don't see this option either.

Multiply both sides by -1:

$3x-4y=-4$

I do see this as a option. So far the only option that works is 2.

Let's look at point slope form now.

We had the point that our line went through was (x1,y1)=(-4,-2) and the slope,m, was 3/4 (we found this earlier).

y-y1=m(x-x1)

Plug in like so:

y-(-2)=3/4(x-(-4))

y+2=3/4 (x+4)

So option 5 looks good too.

7 0

3 years ago

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Please help me with fuction problems.

DerKrebs [107]

1) For each of these, keep in mind vertex form: f(x)=a(x-h)^2+k. With vertex form, a is the direction and width, h is the horizontal placement of the vertex, and k is the vertical placement. For the first one, notice that "a" is positive 1, so it faces up. This means that D, the one facing down, cannot be the answer. "h" is 1, so we will move the vertex to the right one unit (keep in mind (x-h), so if it were to be (h+3) you would move it to the left, not the right). "k" is -3, so we would move the vertex down 3 units. That said, the vertex should be at (1,-3) so the answer is C, or the one right below the first one.

2) The graph of f(x)=|2x| translated 5 units to the left means that h is equal to -5. When we plug -5 into vertex form, it should look like: g(x)=|2(x+5)|. The answer to this is A.

3) The equation for reflection on the x axis is f(x)=-a(x-h)+k. So, if the parent function f(x)=4|x| were to be reflected on the x axis, the function would look like this: g(x)=-4|x|. The answer to this should be B.

4) Since h=1 and k=0 in the function f(x)=-3|x-1|, the vertex will be (1,0).

5) This can also be written as g(x)=|x|-3. This means that k=-3, and will be a vertical translation of 3 units down.

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3 years ago

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What is 29.2 x 3/4 I need a the answer please

Stolb23 [73]

Let me help you!!! ok, so remember, it is always easier when you are multiplying one fraction, and one decimal, to keep it simple, and make it either both decimals, or both fractions! so, for instance, i will change the 3/4 into a decimal:
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3 years ago

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How many solutions are there?

e-lub [12.9K]

The answer should be two

5 0

3 years ago