Question

Determine two pairs of polar coordinates for the point (2, -2) with 0° ≤ θ < 360°.

Answer 1

Polar coordinates means you need r (the magnitude) and the angle θ.

Your point (x, y) is (2, -2)

r^2 = x^2 + y^2

Find θ using tan θ = y/x (then use inverse tan to find θ)

Answer 2

i got r=0
and θ 45

Answer 3

r^2 = x^2 + y^2... i think you may not have squared them, since (-2)^2 = 4

45 is correct.

Answer 4

-45 is the angle, not +45.

Answer 5

i still get 0

Answer 6

r^2 = 2^2 + (-2)^2 =

Answer 7

8 but if i square it 4?

Answer 8

No it's just square root of 8, but you can simplify \[\large r = \sqrt 8 = \sqrt 4 \sqrt 2 = 2 \sqrt 2\]

Answer 9

(2 square root of 2, 45°), (-2 square root of 2, 225°)

Answer 10

The angle is -45, so we can add 360 to that to get 315

so one is (2 square root of 2, 315°)

Answer 11

the other, we can make r = -2sqrt2, and subtract 180 from the angle 315

Answer 12

wait so am i right

Answer 13

(2 square root of 2, 45°), (-2 square root of 2, 225°) aren't correct

Answer 14

well the second is, first isn't

Answer 15

(2 square root of 2, 135°), (-2 square root of 2, 315°)

Answer 16

Wait, no, we had one already: (2 square root of 2, 315°)

Answer 17

all you have to do is make r negative, and subtract 180 from the angle, that's your other

Answer 18

(2 square root of 2, 315°), (-2 square root of 2, 135°)

Answer 19

Good :)