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3 years ago

How do you do this question?

Mathematics

2 answers:

beks73 [17]3 years ago

8 0

The length of a circular arc (s) is the product of the circle's radius and the central angle measure in radians.

... s = r·θ

Then the central angle measure in radians is ...

... θ = s/r

For your problem, you have s = 8π/9 and r = 1. Then the central angle AOC is

... ∠AOC = (8π/9)/(1) = 8π/9 . . . . radians

The relationship between radians and degrees is

... 180° = π radians

Multiplying this equation by 8/9 will tell us the degree measure of ∠AOC.

... 8/9×180° = (8/9)×π radians

... ∠AOC = (8/9)·180° = 160°

We know that this is the sum of the two (equal) central angles ∠AOB and ∠BOC, so we have

... 2×∠AOB = 160°

... ∠AOB = 160°/2 = 80°

_____

Here, you know that 8π/9 is the central angle in radians because the ratio of arc length to radius is the angle in radians.

Hitman42 [59]3 years ago

4 0

The central angle corresponding to AOB is half of the 8pi/9 radians mentioned, meaning that the central angle of AOB is 4pi/9.

Converting that to degrees:

4pi/9 180 degrees

-------- * -------------------- = 80 degrees.

1 pi

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BRANLIEST TO FIRST CORRECT ANSWER:

Nuetrik [128]

It would be...C?? I'm not sure but I think it's right. Brainliest?

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3 years ago

The daily profit P (in thousands of dollars) from the sale of televisions is a function of the number x of televisions sold (

scZoUnD [109]

Answer:

The break-even sales amounts is 36 or 224.

Step-by-step explanation:

Consider the provided function.

$P= -5x^2 + 13x - 4$

Where x is the number of televisions sold (in hundreds) and P is the profit.

We need to calculate the break-even sales amounts.

the break-even sales amounts is the sales amounts that result in no profit or loss.

That means substitute P=0 and solve for x.

$-5x^2 + 13x - 4=0$

$5x^2-13x+4=0$

$\mathrm{For\:a\:quadratic\:equation\:of\:the\:form\:}ax^2+bx+c=0\mathrm{\:the\:solutions\:are\:}\\x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

Substitute a=4, b=-13 and c=4 in above formula.

$x_{1,\:2}=\frac{-\left(-13\right)\pm \sqrt{\left(-13\right)^2-4\cdot \:5\cdot \:4}}{2\cdot \:5}$

$x_{1,\:2}=\frac{13\pm\sqrt{169-80}}{10}$

$x_{1,\:2}=\frac{13\pm\sqrt{89}}{10}$

$x=\frac{13+\sqrt{89}}{10},\:x=\frac{13-\sqrt{89}}{10}\\x\approx2.243, \ or\ x\approx 0.357$

Therefore, the break-even sales amounts is 36 or 224.

7 0

3 years ago

HUDSON HAS TO FILL A POT WITH 1 QUART OF WATER. ALL HE HAS IS 1/4 CUP MEASURING CUP. HOW MANY TIMES DOES HE HAVE TO FILL THE 1/4

Marta_Voda [28]

There are 4 cups in a quart.

So if Hudson has only a 1/4 measuring cup, this can be represented by the equation:

4/1/4, solving it we get: 4* 4 (dividing turns a fraction into its reciprocal)

So, 4*4=16

Hudson will have to fill the 1/4 measuring cup 16 times to get a quart.

I hope this helps!

4 0

3 years ago

Read 2 more answers

Write each expression using exponents: 4*4*4*4*4

erastova [34]

Answer:4^6

Step-by-step explanation:

The number of times a term is multiplied is the exponent you use.

In this problem

4 is multiplied 6 times.

Therefore: 4*4*4*4*4*4=4^6

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2 years ago

find the equation of a circle which passes through the point (2,-2) and (3,4) and whose centre lies on the line x+y=2

Nadusha1986 [10]

Answer:

Equation of the circle

(x - 0.7)² + (y - 1.3)² = 12.58

Step-by-step explanation:

The formula for the equation of a circle is given as:

(x - a)² + (y - b)² = r²,

where(a, b) is the center of the circle and r = radius of the circle.

a) We are told in the question that the equation of the circle passes through point(2, -2)

Hence,

Substituting 2 for x and -2 for y in the equation of the circle.

(x - a)² + (y - b)² = r²

(2 - a)² +(-2 - b)² = r²

Expanding the bracket

(2 - a) (2 - a) + (-2 - b)(-2 - b) = r²

4 - 2a - 2a +a² +4 +2b +2b +b² = r²

4 - 4a + a² + 4 + 4b + b² = r²

a² + b² -4a + 4b + 4 + 4 = r²

a² + b² -4a + 4b + 8 = r²............Equation 1

We are also told that the equation of the circle also passes through point (3,4) also, where 3 = x and 4 = y

Hence,

Substituting 3 for x and 4 for y in the equation of the circle.

(x - a)² + (y - b)² = r²

(3 - a)² +(4 - b)² = r²

Expanding the bracket

(3 - a) (3 - a) + (4 - b)(4- b) = r²

9 - 3a - 3a +a² +16 -4b -4b +b² = r²

9 -6a + a² + 16 -8b + b² = r²

a² + b² -6a -8b + 9 + 16 = r²

a² + b² -6a -8b + 25 = r²..........Equation 2

The next step would be to subtract Equation 1 from Equation 2

a² + b² -4a + 4b + 8 - (a² + b² -6a -8b + 25) = r² - r²

a² + b² -4a + 4b + 8 - a² - b² +6a +8b - -25= r² - r²

Collecting like terms

a² - a² + b² - b² - 4a + 6a + 4b + 8b +8- 25 = 0

2a + 12b -17 = 0

2a + 12b = 17...........Equation 3

Step 2

We are going to have to find the values of a and b in other to get our equation of the circle.

Since the center of the circle(a, b) lies on x + y = 2

Therefore, we have

a + b = 2

a = 2 - b

2a + 12b = 17 ..........Equation 3

Substituting 2 - b for a in

2(2 - b) + 12b = 17

4 - 2b + 12b = 17

4 + 10b = 17

10b = 17 - 4

10b = 13

b = 13/10

b = 1.3

Substituting 1.3 for b in

a + b = 2

a + 1.3 = 2

a = 2 - 1.3

a = 0.7

hence, a = 0.7, b = 1.3

Step 3

We have to find the value of r using points (2, -2)

(x - a)² + (y - b)² = r²

Where x = 2 and y = -2

(-2 - 0.7)² + (-2 - 1.3)² = r²

(-2.7)² + (-3.3)² = r²

1.69 + 10.89 = r²

r² = 12.58

r = √12.58 = 3.55

Step 4

The formula for the equation of a circle is given as:

(x - a)² + (y - b)² = r²,

where(a, b) is the center of the circle and r = radius of the circle

a = 0.7

b = 1.3

r² = 12.58

Equation of the circle =

(x - 0.7)² + (y - 1.3)² = 12.58

7 0

3 years ago