Question

Medal + Fan help please!
Determine two pairs of polar coordinates for the point (4, -4) with 0° ≤ θ < 360°

Answer 1

well what is the angle that point makes with the x axis:
use arctan(y/x)

Answer 2

then what?

Answer 3

well if you do that you find its -45o
then you can use the distance formula to find the distance the point is from the origin

Answer 4

right i got -45 what's the distance formula?

Answer 5

is it these?
x = radius×cos(theta)
y = radius×sin(theta)

Answer 6

for this it will be
d = sqrt(x^2+y^2)

Answer 7

ok so that equals 0 @Brandon77

Answer 8

no
d = sqrt( (4)^2 + (-4)^2 ) = sqrt ( 16 + 16 ) = sqrt(32)

Answer 9

oops my bad put it into calc wrong. what next?

Answer 10

so one coordinate can be (sqrt(32),-45o)

Answer 11

how would we find the other one?

Answer 12

if you have a negative radius then it basically mirrors you line. so if the radius is -sqrt(32) then you can add 180o to your angle and get back to the same line

Answer 13

Thanks a lot!

Answer 14

no problem. :)

Answer 15

just to make sure it should be (-sqrt(32),135o)

Answer 16

45+180=225 @Brandon77 ?

Answer 17

but its -45 + 180