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3 years ago

The circumference of a circle can be found using the

Mathematics

1 answer:

RUDIKE [14]3 years ago

7 0

Answer:

C /2pi = r

Step-by-step explanation:

The circumference of a circle is given by

C = 2 * pi*r

We want to solve for r

Divide each side by 2 pi

C / 2pi = 2*pi*r / 2pi

C /2pi = r

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Which of the following is not equal to sin⁡(-230°)?

xenn [34]

From trigonometry we know that:

if $sin(\theta)=sin(\alpha)$

then, $\theta=n\pi+(-1)^n\alpha$ (where $n$ is an integer)

This can be rewritten in degrees as:

$\theta=n(180^{\circ})+(-1)^n\alpha$ .............(Equation 1)

Now, in our case, $\alpha=-230^{\circ}$

Therefore, (Equation 1) can be written as:

$\theta=n(180^{\circ})+(-1)^n(-230^{\circ})$ ..........(Equation 2)

Now, to find the correct options all that we have to do is replace n by relevant integers and find the values of $\theta$ that match.

For n=2, (Equation 2) gives us: $\theta=2\times 180^{\circ}+(-1)^2(-230^{\circ})=360^{\circ}-230^{\circ}=130^{\circ}$ .

Thus, $sin(230^{\circ})=sin(130^{\circ})$

Now, we know that: $-sin(-50^{\circ})=sin(50^{\circ})$

Let n=-1, then:

$\theta=(-1)\times 180^{\circ}+(-1)^{-1}(-230^{\circ})=-180^{\circ}+230^{\circ}=50^{\circ}$

Thus, $sin(-230^{\circ})=-sin(-50^{\circ})$

Likewise, $sin(-230^{\circ})=sin(50^{\circ})$

Only the last option $sin(-50^{\circ})$ will never match $sin(-230^{\circ})$ because no integral value of $n$ will ever give $\theta=-50^{\circ}$

Thus the last option is the correct option.

3 0

3 years ago

Read 2 more answers

What is the equation of this line?

ikadub [295]

Answer:

y=4/3x-1/3

Step-by-step explanation:

m=y2-y1/x2-x1

fill in the two points for the y's and the x's

then proceed to y = mx+b

Where:

m is the slope, and

b is the y-intercept

then you solve and <u>bam</u>!

8 0

3 years ago

A block of concrete is 1m long, 50cm wild and 4cm thick. 1.calculate the volume of the block in cm3 .2.if 1cm has a mass of 2.7g

Nonamiya [84]

9514 1404 393

Answer:

20,000 cm³
54 kg

Step-by-step explanation:

1 m is 100 cm, so the volume is ...

V = LWH

V = (100 cm)(50 cm)(4 cm) = 20,000 cm³ . . . volume

The mass is ...

(20,000 cm³)(2.7 g/cm³) = 54,000 g = 54 kg

The mass of the block is 54 kg.

7 0

3 years ago

Graph each circle given below right the center and the radius of each circle

Paraphin [41]

Answer:

Center: (-1,8)

Radius: 1

The graph is attached.

Step-by-step explanation:

The equation of the circle has the form:

$(x -h)^{2}+(y-k)^{2}=r^{2}$

Where (h,k) is the point of the center of the circle and r is the radius of the circle.

The equation given in the problem is

$(x +1)^{2}+(y-8)^{2}=1$

Therefore:

h=-1

k=8

Then, the center is (-1,8) and radius is 1.

You can graph the circle with its center at the (-1,8) and a radius of 1 as you can see in the figure attached.

4 0

4 years ago

Read 2 more answers

Find the slope of the line

exis [7]

the slope of the line is y = -1/2x -2
<3

6 0

3 years ago