Question

(Trigonometry) How to convert 2x - 3y = 5 to polar form?

Answer 1

@uri

Answer 2

Do you know Trig?

Answer 3

You're in which grade?

Answer 4

Going to be a Senior.

Answer 5

12th

Answer 6

Oh which group? I mean Commerce?

Answer 7

Sorry, I'm in High School.

Answer 8

Oh okay cool,I'm just 12 so no idea about it. :)

Answer 9

Man... Nobody can answer this...

Answer 10

@jim_thompson5910 Can :D

Answer 11

@jim_thompson5910

Answer 12

:)

Answer 13

hint:

x = r*cos(theta)
y = r*sin(theta)

make sure you solve for r once you've made all the substitutions

Answer 14

I got as far as 5/r=2cos(theta)-3sin(theta), but I think that it is wrong...

Answer 15

2x - 3y = 5

2*r*cos(theta) - 3*r*sin(theta) = 5

r*(2*cos(theta) - 3*sin(theta)) = 5

r = 5/(2*cos(theta) - 3*sin(theta))


so you were (kinda) close

Answer 16

not sure how you got 5/r though

Answer 17

For this one, would it be r^2=sqrt(10)/2 ?

Answer 18

what do you mean

Answer 19

x2 + y2 = 10 My bad... That is the starting equation...

Answer 20

Oh, but it would be jut r=sqrt(10)/2

Answer 21

Right?

Answer 22

oh this is a circled centered at (0,0) with radius sqrt(10)

Answer 23

so it's just r = sqrt(10)

since r is the radius

Answer 24

Oh! I see. I think that I am over-complicating this...

Answer 25

possibly, but that's what polar form is essentially: each point in the coordinate space is defined by the angle and how far it is from the center

think of it like you're on a navy battleship and you are looking at the radar

Answer 26

and you can think of the angle as the direction you need to look in to see the point

Answer 27

I think I understand.

So for x^2 - y^2 = 4 (You may leave your answer for this one as r2)

It is r^2=sqrt(-2), and that is it, right?

Answer 28

hmm no that's a bit off

Answer 29

*sigh* I am bad at these...

Answer 30

x^2 - y^2 = 4


(r*cos(theta))^2 - (r*sin(theta))^2 = 4


r^2*cos^2(theta) - r^2*sin^2(theta) = 4


r^2(cos^2(theta) - sin^2(theta)) = 4


r^2*cos(2theta) = 4


r^2 = 4/cos(2theta)


r = sqrt( 4/cos(2theta) )

Answer 31

its ok, just keep practicing

Answer 32

All right, well thanks bunches. You gave me a couple examples to go off of :)

Answer 33

you're welcome