The Cartesian coordinates of a point are given. (a) (6, −6) (i) Find polar coordinates (r, θ) of the point, where r > 0 and 0 ≤ θ < 2π. (r, θ) = $ Correct: Your answer is correct. (ii) Find polar coordinates (r, θ) of the point, where r < 0 and 0 ≤ θ < 2π. (r, θ) = $ Correct: Your answer is correct. (b) (−1, 3 ) (i) Find polar coordinates (r, θ) of the point, where r > 0 and 0 ≤ θ < 2π. (r, θ) = $ Correct: Your answer is correct. (ii) Find polar coordinates (r, θ) of the point, where r < 0 and 0 ≤ θ < 2π. (r, θ) = $ Correct: Your answer is correct.

Respuesta :

Answer:

Part a)

(i) The polar coordinates are [tex](6\sqrt{2},\frac{7\pi}{4})[/tex]

(ii) The polar coordinates are [tex](-6\sqrt{2},\frac{3\pi}{4})[/tex]

Part b)

(i)The polar coordinates are [tex](\sqrt{10},0.60\pi)[/tex]

(ii)The polar coordinates are [tex](-\sqrt{10},1.60\pi)[/tex]

Step-by-step explanation:

Part a) we have

(6,-6)

(i) Find polar coordinates (r, θ) of the point, where r > 0 and 0 ≤ θ < 2π

step 1

Find r

[tex]r^{2}=x^{2} + y^{2}[/tex]

substitute

[tex]r^{2}=(6)^{2} + (-6)^{2}[/tex]

[tex]r^{2}=72[/tex]

[tex]r=6\sqrt{2}[/tex]

step 2

Find angle theta

[tex]tan(\theta)=\frac{y}{x}[/tex]

substitute

[tex]tan(\theta)=\frac{6}{6}=1[/tex]

[tex]\theta=arctan(1)=\frac{\pi}{4}[/tex]

Remember that the point (6,-6) lies on IV quadrant

so

The angle theta is equal to

[tex]2\pi-\frac{\pi}{4}=\frac{7\pi}{4}[/tex]  

therefore

The polar coordinates are [tex](6\sqrt{2},\frac{7\pi}{4})[/tex]

(ii) Find polar coordinates (r, θ) of the point, where r < 0 and 0 ≤ θ < 2π.

For r< 0 the point lies on II Quadrant

so

the angle theta is equal to

[tex]\pi-\frac{\pi}{4}=\frac{3\pi}{4}[/tex]  

therefore

The polar coordinates are [tex](-6\sqrt{2},\frac{3\pi}{4})[/tex]

Part b) we have

(-1,3)

(i) Find polar coordinates (r, θ) of the point, where r > 0 and 0 ≤ θ < 2π

step 1

Find r

[tex]r^{2}=x^{2} + y^{2}[/tex]

substitute

[tex]r^{2}=(-1)^{2} + (3)^{2}[/tex]

[tex]r^{2}=10[/tex]

[tex]r=\sqrt{10}[/tex]

step 2

Find angle theta

[tex]tan(\theta)=\frac{y}{x}[/tex]

substitute

[tex]tan(\theta)=\frac{3}{1}=3[/tex]

[tex]\theta=arctan(3)=0.40\pi[/tex]

Remember that the point (-1,3) lies on II quadrant

so

The angle theta is equal to

[tex]\pi-0.40\pi=0.60\pi[/tex]

therefore

The polar coordinates are [tex](\sqrt{10},0.60\pi)[/tex]

(ii) Find polar coordinates (r, θ) of the point, where r < 0 and 0 ≤ θ < 2π.

For r< 0 the point lies on IV Quadrant

so

the angle theta is equal to

[tex]2\pi-0.40\pi=1.60\pi[/tex]

therefore

The polar coordinates are [tex](-\sqrt{10},1.60\pi)[/tex]