Deck 65: Polar Coordinates

Question 1

Find the rectangular coordinates of the point given in polar coordinates.Round your results to two decimal places.​ $$\left( 8 , \frac { 7 \pi } { 5 } \right)$$ ​

A)Rectangular coordinates: (7.61,0.07)
B)Rectangular coordinates: (7.61,-7.61)
C)Rectangular coordinates: (-2.47,-7.61)
D)Rectangular coordinates: (-2.47,7.61)
E)Rectangular coordinates: (-2.47,0.07)

Answer 1

Rectangular coordinates: (-2.47,-7.61)

Question 2

A point in rectangular coordinates is given.Convert the point to polar coordinates,r > 0.​ $( 2,2 )$ ​

A)Polar coordinates: $$\left( - \sqrt { 2 } , \frac { \pi } { 4 } \right)$$
B)Polar coordinates: $$\left( \sqrt { 8 } , \frac { \pi } { 4 } \right)$$
C)Polar coordinates: $$\left( - \sqrt { 8 } , \frac { \pi } { 4 } \right)$$
D)Polar coordinates: $\left( \sqrt { 8 } , - \frac { \pi } { 4 } \right)$
E)Polar coordinates: $\left( \sqrt { 2 } , \frac { \pi } { 4 } \right)$

Answer 2

Polar coordinates: $$\left( \sqrt { 8 } , \frac { \pi } { 4 } \right)$$

Question 3

A point (a,b)= (r,θ)shown in below graph in polar coordinates is given.Convert the point to rectangular coordinates.​ ​ $$a = 5 , b = - \pi$$ ​

A)Rectangular coordinates: (5,0)
B)Rectangular coordinates: (5,5)
C)Rectangular coordinates: (-5,5)
D)Rectangular coordinates: (-5,0)
E)Rectangular coordinates: (0,5)

Answer 3

Rectangular coordinates: (-5,0)

Question 4

Find the rectangular coordinates of the point given in polar coordinates.Round your results to two decimal places.​ $$( 3.5,1.62 )$$ ​

A)Rectangular coordinates: (3.5,1.62)
B)Rectangular coordinates: (4.50,0.83)
C)Rectangular coordinates: (-0.17,3.50)
D)Rectangular coordinates: (0.83,4.50)
E)Rectangular coordinates: (3.50,-0.17)

Question 5

Find the rectangular coordinates of the point given in polar coordinates.Round your results to two decimal places.​ $$( 8.98,3.0 )$$ ​

A)Rectangular coordinates: (2.27,-7.89)
B)Rectangular coordinates: (-7.89,2.27)
C)Rectangular coordinates: (1.27,-8.89)
D)Rectangular coordinates: (-8.89,1.27)
E)Rectangular coordinates: (8.98,4.50)

Question 6

A point in rectangular coordinates is given.Convert the point to polar coordinates,r > 0.​ $( 0,4 )$ ​

A)Polar coordinates: $\left( 4 , - \frac { \pi } { 2 } \right)$
B)Polar coordinates: $\left( - 4 , - \frac { \pi } { 2 } \right)$
C)Polar coordinates: $\left( 4 , \frac { \pi } { 2 } \right)$
D)Polar coordinates: $\left( - 4 , \frac { 3 \pi } { 2 } \right)$
E)Polar coordinates: $\left( 4 , \frac { 3 \pi } { 2 } \right)$

Question 7

Find the rectangular coordinates of the point given in polar coordinates.Round your results to two decimal places.​ $$( - 5.7 , - 0.8 )$$ ​

A)Rectangular coordinates: (-3.97,5.09)
B)Rectangular coordinates: (-2.97,5.09)
C)Rectangular coordinates: (-3.97,4.09)
D)Rectangular coordinates: (-2.97,4.09)
E)Rectangular coordinates: (4.09,-3.97)

Question 8

A point in polar coordinates is given.Convert the point to rectangular coordinates.Round your answers to one decimal places.​ $$( - 2.1,1.1 )$$ ​

A)Rectangular coordinates: (1.9,1.0)
B)Rectangular coordinates: (-1.0,-1.9)
C)Rectangular coordinates: (2.1,1.1)
D)Rectangular coordinates: (-1.9,-1.0)
E)Rectangular coordinates: (1.0,1.9)

Question 9

Find the rectangular coordinates of the point given in polar coordinates.Round your results to two decimal places.​ $$\left( 2 , \frac { 2 \pi } { 15 } \right)$$ ​

A)Rectangular coordinates: (1.83,-0.81)
B)Rectangular coordinates: (1.83,1.83)
C)Rectangular coordinates: (-0.81,0.81)
D)Rectangular coordinates: (1.83,0.15)
E)Rectangular coordinates: (1.83,0.81)

Question 10

A point in rectangular coordinates is given.Convert the point to polar coordinates,r > 0.​ $( - 2,0 )$ ​

A)​​Polar coordinates: $( - 2,2 \pi )$ ​
B)Polar coordinates: $( - 2 , \pi )$
C)Polar coordinates: $$( 2,2 \pi )$$
D)Polar coordinates: $$\left( 2 , \frac { \pi } { 2 } \right)$$
E)Polar coordinates: $( 2 , \pi )$

Question 11

A point in rectangular coordinates is given.Convert the point to polar coordinates,r > 0.​ $( 0 , - 6 )$ ​

A)Polar coordinates: $\left( - 6 , \frac { 3 \pi } { 2 } \right)$
B)Polar coordinates: $\left( 6 , - \frac { \pi } { 2 } \right)$
C)Polar coordinates: $\left( 6 , \frac { \pi } { 2 } \right)$
D)Polar coordinates: $\left( - 6 , - \frac { \pi } { 2 } \right)$
E)Polar coordinates: $\left( 6 , \frac { 3 \pi } { 2 } \right)$

Question 12

A point in polar coordinates is given.Convert the point to rectangular coordinates.Round your answers to one decimal places.​ $$( - 6,3.56 )$$ ​

A)Rectangular coordinates: (3.6,6.0)
B)Rectangular coordinates: (5.5,2.4)
C)Rectangular coordinates: (-5.5,-2.4)
D)Rectangular coordinates: (-2.4,-5.5)
E)Rectangular coordinates: (2.4,5.5)

Question 13

Find the rectangular coordinates of the point given in polar coordinates.Round your results to two decimal places.​ $$( 5,1.5 )$$ ​

A)Rectangular coordinates: (4.89,0.35)
B)Rectangular coordinates: (-4.89,0.35)
C)Rectangular coordinates: (-0.35,4.89)
D)Rectangular coordinates: (0.35,4.89)
E)Rectangular coordinates: (5,1.5)

Question 14

Find the rectangular coordinates of the point given in polar coordinates.Round your results to two decimal places.​ $$( 5.8,2.62 )$$ ​

A)Rectangular coordinates: (-5.03,2.89)
B)Rectangular coordinates: (5.80,2.89)
C)Rectangular coordinates: (2.89,-5.03)
D)Rectangular coordinates: (-4.03,3.89)
E)Rectangular coordinates: (3.89,-4.03)

Question 15

Find the rectangular coordinates of the point given in polar coordinates.Round your results to two decimal places.​ $$( 7.2 , - 3.0 )$$ ​

A)Rectangular coordinates: (-7.13,-1.02)
B)Rectangular coordinates: (-1.02,-7.13)
C)Rectangular coordinates: (-6.13,-1.02)
D)Rectangular coordinates: (-7.13,-0.02)
E)Rectangular coordinates: (-6.13,-0.02)

Question 16

A point (a,b)shown in below graph in polar coordinates is given.Convert the point to rectangular coordinates.​ ​ $$a = 6 , b = \frac { \pi } { 2 }$$ ​

A)Rectangular coordinates: (6,6)
B)Rectangular coordinates: (6,0)
C)Rectangular coordinates: (0,6)
D)Rectangular coordinates: (-6,0)
E)Rectangular coordinates: (0,-6)

Question 17

A point in rectangular coordinates is given.Convert the point to polar coordinates,r > 0.​ $( 2,0 )$ ​

A)Polar coordinates: $( 0 , - 2 )$
B)Polar coordinates: $( 0,2 )$
C)Polar coordinates: $( - 2,2 )$
D)Polar coordinates: $( - 2,0 )$
E)Polar coordinates: $( 2,0 )$

Question 18

A point (a,b)shown in below graph in polar coordinates is given.Convert the point to rectangular coordinates.​ ​ $$a = 3 , b = \frac { 3 \pi } { 2 }$$ ​

A)Rectangular coordinates: (0,3)
B)Rectangular coordinates: (-3,0)
C)Rectangular coordinates: (3,0)
D)Rectangular coordinates: (0,-3)
E)Rectangular coordinates: (3,3)

Question 19

A point in rectangular coordinates is given.Convert the point to polar coordinates,r > 0.​ $( - 13 , - 13 )$ ​

A)Polar coordinates: $\left( \sqrt { 338 } , \frac { 5 \pi } { 4 } \right)$
B)Polar coordinates: $\left( - \sqrt { 338 } , \frac { 5 \pi } { 4 } \right)$
C)Polar coordinates: $\left( - \sqrt { 13 } , \frac { \pi } { 4 } \right)$
D)Polar coordinates: $\left( \sqrt { 13 } , \frac { \pi } { 4 } \right)$
E)Polar coordinates: $\left( \sqrt { 338 } , - \frac { \pi } { 4 } \right)$

Question 20

A point in rectangular coordinates is given.Convert the point to polar coordinates,r > 0.​ $$( - 7,7 )$$ ​

A)Polar coordinates: $\left( - \sqrt { 7 } , \frac { \pi } { 4 } \right)$
B)Polar coordinates: $\left( \sqrt { 98 } , \frac { 3 \pi } { 4 } \right)$
C)Polar coordinates: $\left( \sqrt { 98 } , - \frac { 3 \pi } { 4 } \right)$
D)Polar coordinates: $\left( - \sqrt { 98 } , \frac { 3 \pi } { 4 } \right)$
E)Polar coordinates: $\left( \sqrt { 7 } , \frac { \pi } { 4 } \right)$

Question 21

Use a graphing utility to find one set of polar coordinates for the point given in rectangular coordinates,r > 0.Round your answers to three decimal places.​ $( 3 , - 2 )$ ​

A)Polar coordinates: $( \sqrt { 2 } , - 0.588 )$
B)Polar coordinates: $( \sqrt { 1 } , - 0.588 )$
C)Polar coordinates: $( \sqrt { 13 } , - 0.588 )$
D)Polar coordinates: $( \sqrt { 13 } , 0.588 )$
E)Polar coordinates: $( \sqrt { 3 } , - 0.588 )$

Question 22

Convert the rectangular equation to polar form.Assume r > 1.​ $5 x + 7 y - 4 = 0$ ​

A) $y = \frac { - 4 } { 5 \cos \Theta - 7 \sin \theta }$
B) $y = \frac { - 4 } { 5 \cos \Theta + 7 \sin \theta }$
C) $y = \frac { 4 } { 5 \cos \Theta - 7 \sin \theta }$
D) $y = \frac { 4 } { 5 \cos \Theta + 7 \sin \theta }$
E) $y = \frac { 1 } { 5 \cos \Theta + 7 \sin \theta }$

Question 23

Convert the rectangular equation to polar form.Assume a > 0,r > 1.​ $x ^ { 2 } + y ^ { 2 } = 4 a ^ { 2 }$ ​

A) $r = 2 a$
B) $r = - 42 a$
C) $r = 2$
D) $r = - 2 a ^ { 2 }$
E) $r = 2 a ^ { 2 }$

Question 24

Convert the rectangular equation to polar form.Assume r > 1.​ $x = 15$ ​

A) $r = 15 \sec \theta$
B) $r = \csc \theta$
C) $r = 15 \sin \theta$
D) $r = 15 \csc \theta$
E) $r = 15 \cos \theta$

Question 25

Convert the rectangular equation to polar form.Assume a > 0,r > 0.​ $x ^ { 2 } + y ^ { 2 } - 5 a x = 0$ ​

A) $r = 5 a \sin \theta$
B) $r = 5 a \cot \Theta$
C) $r = 5 \operatorname { acsc } \theta$
D) $r = 5 a \cos \theta$
E) $r = 5 \operatorname { asec } \theta$

Question 26

Convert the rectangular equation to polar form.Assume r > 1.​ $x ^ { 2 } + y ^ { 2 } = 49$ ​

A) $r = 7$
B) $r = - 7$
C) $r = \frac { 1 } { 7 }$
D) $r = 49$
E) $r = - \frac { 1 } { 7 }$

Question 27

Convert the rectangular equation to polar form.Assume r > 1.​ $x y = 13$ ​

A) $r ^ { 2 } = 13 \sec 2 \theta$
B) $r ^ { 2 } = 26 \csc 2 \theta$
C) $r ^ { 2 } = 26 \cos 2 \theta$
D) $r ^ { 2 } = 13 \csc 2 \theta$
E) $r ^ { 2 } = 26 \sec 2 \Theta$

Question 28

A point in rectangular coordinates is given.Convert the point to polar coordinates,r > 0.​ $( - \sqrt { 19 } , \sqrt { 19 } )$ ​

A)Polar coordinates: $\left( \sqrt { 38 } , \frac { 3 \pi } { 4 } \right)$
B)Polar coordinates: $\left( \sqrt { 38 } , - \frac { \pi } { 4 } \right)$
C)Polar coordinates: $\left( \sqrt { 38 } , - \frac { 3 \pi } { 4 } \right)$
D)Polar coordinates: $\left( \sqrt { 38 } , \frac { \pi } { 4 } \right)$
E)Polar coordinates: $\left( \sqrt { 38 } , \frac { 5 \pi } { 4 } \right)$

Question 29

Convert the rectangular equation to polar form.Assume r > 1.​ $y = - 3$ ​

A) $r = - 3 \sec \theta$
B) $r = - 3 \csc \theta$
C) $r = - \csc \theta$
D) $r = - 3 \cos \theta$
E) $r = - 3 \sin \theta$

Question 30

Convert the rectangular equation to polar form.Assume r > 1.​ $y = 6$ ​

A) $r = 6 \csc \theta$
B) $r = 6 \cos \theta$
C) $r = 6 \cot \theta$
D) $r = 6 \sin \theta$
E) $r = 6 \sec \theta$

Question 31

Convert the rectangular equation to polar form.Assume r > 1.​ $x = 17 a$ ​

A) $r = \operatorname { acsc } \theta$
B) $r = 17 \mathrm { a } \cos \theta$
C) $r = 17 \sin \theta$
D) $r = 17 \operatorname { acsc } \theta$
E) $r = 17 \text { asec } \theta$

Question 32

Convert the rectangular equation to polar form.Assume r > 1.​ $7 x - y + 6 = 0$ ​

A) $y = \frac { - 6 } { 7 \cos \Theta - 6 \sin \theta }$
B) $y = \frac { - 7 } { 6 \cos \Theta - \sin \Theta }$
C) $y = \frac { - 6 } { 7 \cos \theta + \sin \theta }$
D) $y = \frac { 6 } { 7 \cos \theta - \sin \theta }$
E) $y = \frac { - 6 } { 7 \cos \theta - \sin \theta }$

Question 33

Convert the polar equation to rectangular form.​ $r = 3 \cos \theta$ ​

A) $x ^ { 2 } + y ^ { 2 } + 3 y = 0$
B) $x ^ { 2 } + y ^ { 2 } - 3 = 0$
C) $x ^ { 2 } + y ^ { 2 } - 3 y = 0$
D) $x ^ { 2 } + y ^ { 2 } + 3 x = 0$
E) $x ^ { 2 } + y ^ { 2 } - 3 x = 0$

Question 34

Convert the rectangular equation to polar form.Assume a > 0,r > 1.​ $x ^ { 2 } + y ^ { 2 } - 3 a y = 0$ ​

A) $r = 3 a \sin \theta$
B) $r = 3 a \cot \Theta$
C) $r = 3 a \cos \theta$
D) $r = 3 \operatorname { asec } \theta$
E) $r = 3 \operatorname { acsc } \theta$

Question 35

Convert the rectangular equation to polar form.Assume r > 1.​ $y = 2$ ​

A) $r = 2 \cos \theta$
B) $r = \csc \theta$
C) $r = 2 \csc \theta$
D) $r = 2 \sin \theta$
E) $r = 2 \sec \theta$

Question 36

A point in rectangular coordinates is given.Convert the point to polar coordinates.Round your answers to two decimal places,r > 0.​ $( 11,13 )$ ​

A)Polar coordinates: $( \sqrt { 290 } , - 0.87 )$
B)Polar coordinates: $( \sqrt { 11 } , - 0.87 )$
C)Polar coordinates: $( \sqrt { 13 } , 0.87 )$
D)Polar coordinates: $( \sqrt { 11 } , 0.87 )$
E)Polar coordinates: $( \sqrt { 290 } , 0.87 )$

Question 37

A point in rectangular coordinates is given.Convert the point to polar coordinates,r > 0.​ $( - \sqrt { 3 } , - \sqrt { 3 } )$ ​

A)Polar coordinates: $\left( \sqrt { 6 } , - \frac { \pi } { 4 } \right)$
B)Polar coordinates: $\left( \sqrt { 6 } , - \frac { 5 \pi } { 4 } \right)$
C)Polar coordinates: $\left( \sqrt { 6 } , \frac { 5 \pi } { 4 } \right)$
D)Polar coordinates: $\left( \sqrt { 6 } , \frac { \pi } { 4 } \right)$
E)Polar coordinates: $\left( \sqrt { 6 } , \frac { 3 \pi } { 4 } \right)$

Question 38

Convert the polar equation to rectangular form.​ $r = - 5 \cos \theta$ ​

A) $x ^ { 2 } + y ^ { 2 } - 5 x = 0$
B) $x ^ { 2 } + y ^ { 2 } - 5 = 0$
C) $x ^ { 2 } + y ^ { 2 } + 5 x = 0$
D) $x ^ { 2 } + y ^ { 2 } - 5 y = 0$
E) $x ^ { 2 } + y ^ { 2 } + 5 y = 0$

Question 39

Convert the polar equation to rectangular form.​ $r = 2 \sin \theta$ ​

A) $x ^ { 2 } + y ^ { 2 } - 2 y = 0$
B) $x ^ { 2 } + y ^ { 2 } + 2 y = 0$
C) $x ^ { 2 } + y ^ { 2 } - 2 \mathrm { x } = 0$
D) $x ^ { 2 } + y ^ { 2 } + 2 \mathrm { x } = 0$
E) $x ^ { 2 } + y ^ { 2 } - 2 = 0$

Question 40

Convert the rectangular equation to polar form.Assume r > 1.​ $\left( x ^ { 2 } + y ^ { 2 } \right) ^ { 2 } = 9 \left( x ^ { 2 } - y ^ { 2 } \right)$ ​

A) $r ^ { 2 } = 9 \cos 2 \theta$
B) $r ^ { 2 } = 9 \csc 2 \theta$
C) $r ^ { 2 } = 9 \cos \theta$
D) $r ^ { 2 } = 9 \sin 2 \theta$
E) $r ^ { 2 } = 9 \sin \theta$

Question 41

Describe the graph of the polar equation and find the corresponding rectangular equation.Select the correct graph.​ $$r = 2 \sec \theta$$ ​

A)The graph of the polar equation is not evident by simple inspection.Convert to rectangular form first.​ $$x - 5 = 0$$ ​
B)The graph of the polar equation is not evident by simple inspection.Convert to rectangular form first.​ $$x - 2 = 0$$ ​
C)The graph of the polar equation is not evident by simple inspection.Convert to rectangular form first.​ $$x + 2 = 0$$ ​
D)The graph of the polar equation is not evident by simple inspection.Convert to rectangular form first.​ $$x - 3 = 0$$ ​
​
E)The graph of the polar equation is not evident by simple inspection.Convert to rectangular form first.​ $$x - 3 = 0$$ ​

Question 42

Convert the polar equation to rectangular form.​ $r ^ { 2 } = 7 \sin \theta$ ​

A) $x ^ { 2 } - y ^ { 2 } - \sqrt [ 3 ] { 49 } y ^ { 2 / 3 } = 0$
B) $x ^ { 2 } + y ^ { 2 } + \sqrt [ 3 ] { 49 } y ^ { 2 / 3 } = 0$
C) $x ^ { 2 } + y ^ { 2 } - \sqrt [ 3 ] { 7 } y ^ { 2 / 3 } = 0$
D) $$x ^ { 2 } + y ^ { 2 } - \sqrt [ 3 ] { 49 } y ^ { 2 / 3 } = 0$$
E) $x ^ { 2 } + y ^ { 2 } + \sqrt [ 3 ] { 7 } y ^ { 2 / 3 } = 0$

Question 43

Convert the polar equation to rectangular form.​ $r = 10$ ​

A) $x ^ { 2 } + y ^ { 2 } = 100 \mathrm { x }$
B) $$x ^ { 2 } + y ^ { 2 } = 100$$
C) $x ^ { 2 } + y ^ { 2 } = - 100$
D) $x ^ { 2 } + y ^ { 2 } = 100 y$
E) $x ^ { 2 } - y ^ { 2 } = 100$

Question 44

Describe the graph of the polar equation and find the corresponding rectangular equation.Select the correct graph.​ $r = 2$ ​

A)The graph of the polar equation consists of all points that are two units from the pole. $x ^ { 2 } + y ^ { 2 } = - 4$
B)The graph of the polar equation consists of all points that are two units from the pole. $$x ^ { 2 } + y ^ { 2 } = 4$$
C)The graph of the polar equation consists of all points that are two units from the pole. $$x ^ { 2 } + y ^ { 2 } = 2$$
D)The graph of the polar equation consists of all points that are two units from the pole. $$x ^ { 2 } + y ^ { 2 } = 4$$
E)The graph of the polar equation consists of all points that are two units from the pole. $$x ^ { 2 } + y ^ { 2 } = 2$$

Question 45

Convert the polar equation to rectangular form.​ $r = \frac { 8 } { 1 + \sin \theta }$ ​

A) $x ^ { 2 } + 16 y - 64 = 0$
B) $x ^ { 2 } + 16 x + 64 = 0$
C) $x ^ { 2 } + 16 y - 64 x = 0$
D) $x ^ { 2 } + 16 y + 64 = 0$
E) $x ^ { 2 } + 16 - 64 = 0$

Question 46

Describe the graph of the polar equation and find the corresponding rectangular equation.Select the correct graph.​ $$r = 7 \csc \theta$$ ​

A)The graph of the polar equation is not evident by simple inspection.Convert to rectangular form first.​ $$y + 7 = 0$$ ​
B)The graph of the polar equation is not evident by simple inspection.Convert to rectangular form first.​ $$y - 6 = 0$$ ​
C)The graph of the polar equation is not evident by simple inspection.Convert to rectangular form first.​ $$y - 9 = 0$$ ​
D)The graph of the polar equation is not evident by simple inspection.Convert to rectangular form first.​ $$y - 7 = 0$$ ​
E)The graph of the polar equation is not evident by simple inspection.Convert to rectangular form first.​ $$y - 8 = 0$$ ​

Question 47

Convert the polar equation to rectangular form.​ $r = 6 \cos 2 \theta$ ​

A) $\left( x ^ { 2 } + y ^ { 2 } \right) ^ { 2 } = 36 \left( x ^ { 2 } - y ^ { 2 } \right) ^ { 2 }$
B) $\left( x ^ { 2 } + y ^ { 2 } \right) ^ { 3 } = 6 \left( x ^ { 2 } - y ^ { 2 } \right) ^ { 3 }$
C) $\left( x ^ { 2 } + y ^ { 2 } \right) ^ { 3 } = 36 \left( x ^ { 2 } - y ^ { 2 } \right) ^ { 3 }$
D) $\left( x ^ { 2 } + y ^ { 2 } \right) ^ { 3 } = 6 \left( x ^ { 2 } - y ^ { 2 } \right) ^ { 2 }$
E) $\left( x ^ { 2 } + y ^ { 2 } \right) ^ { 3 } = 36 \left( x ^ { 2 } - y ^ { 2 } \right) ^ { 2 }$

Question 48

Convert the polar equation to rectangular form.​ $r = - 9 \sec \theta$ ​

A) $y = - 9$
B) $9 x = r$
C) $x = 9$
D) $y = 9$
E) $x = - 9$

Question 49

Convert the polar equation to rectangular form.​ $r = 4 \csc \theta$ ​

A) $y = 4$
B) $y = 4 \mathrm { r }$
C) $x = 4$
D) $6 y = \mathrm { r }$
E) $x = 4 \mathrm { r }$

Question 50

Convert the polar equation to rectangular form.​ $r = - 9 \sin \theta$ ​

A) $x ^ { 2 } + y ^ { 2 } - 9 x = 0$
B) $x ^ { 2 } + y ^ { 2 } - 9 y = 0$
C) $x ^ { 2 } + y ^ { 2 } + 9 \mathrm { x } = 0$
D) $x ^ { 2 } + y ^ { 2 } + 9 y = 0$
E) $x ^ { 2 } + y ^ { 2 } - 9 = 0$