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3 years ago

Convert x2 + y2 -4x = 0 to polar form.

Mathematics

1 answer:

Bingel [31]3 years ago

7 0

Answer:

$r(r-4\cos \theta)=0$

Step-by-step explanation:

We are given the following equation:

$x^2 + y^2 -4x = 0$

We have to convert it into polar form.

We put

$x = r \cos \theta\\y = r\sin \theta$

Putting values, we get:

$x^2 + y^2 -4x = 0\\(r\cos \theta)^2 + (r\sin \theta)^2 - 4(r\cos \theta) = 0\\r^2(\cos^2 \theta + \sin^2 \theta) - 4r\cos \theta = 0\\r^2 - 4r\cos \theta = 0\\r(r-4\cos \theta)=0$

is the required polar form.

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HACTEHA [7]

the correct question is
1. You’re baking a circular cake for a party. Your cake can be any size you want
2. What will the radius of your cake be and how many slices will you be able to cut?
3. List the coordinates of any point in the coordinate plane.For your original discussion post, you only need to respond to #1, #2, and #3.View posts from your classmates and choose one to which you will respond.

Answer the following questions:
1. For the cake that your classmate is baking, what would be the central angle of each slice of cake?
2. If you eat two slices of cake that are side by side, what is the measure of the arc that these two slices intercept?
3. What is the circumference of the cake?
4. A circle to represent the cake is graphed on the coordinate plane. What equation represents the cake if it is centered at the point that your classmate listed for #2?
This is what my classmate posted.
1. The radius of my cake is 6 inches and I can cut 8 pieces.
2. (2,-3)

we know that
1) the radius of the cake is r=6 in and the cake will be cut into 8 pieces
2) the coordinates of any point in the coordinate plane is (2,-3)

part 1) what would be the central angle of each slice of cake?

The central angle of each slice would be found by dividing the total central angle of a circle (360°) by the number of slices (8),
so:
360/8=45 degrees

the answer part 1) is
Each slice would have a central angle of 45°.

Part 2) If you eat two slices of cake that are side by side, what is the measure of the arc that these two slices intercept?

The degree measure of the intercepted arc would be 2*45°=90°

The length in inches of the intercepted arc could be found:
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if 360° (full circle) has a length of---------> 12*pi in
90°----------------------> x
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the formula to calculate the arc length is
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Part 3) What is the circumference of the cake?

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the answer part 3) is
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Part 4) A circle to represent the cake is graphed on the coordinate plane. What equation represents the cake if it is centered at the point that your classmate listed for #2?

we know that
the center is the point (2,-3)
the equation of a circle is
(x-h)²+(y-k)²=r²
where (h,k) is the center
and
r is the radius
so
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the answer part 4) is
(x-2)²+(y+3)²=36

see the attached figure

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