Jump to content

The Math Thread!


Arkhi

Recommended Posts

Alternatively, this thread can be called "Ark hates graphs" thread.
Anyway, the creation of this was probably only a matter of time. I am wondering if someone well-suited in the caliber of Calculus would be able to assist me.
I need to convert the following polar equation into its rectangular equation:

r=6/(2-3sinθ)

Or, if you work visually, here's a picture (Number 25):

Link to comment
Share on other sites

4x^2 + 3y^2 + 36y - 36 = 0

if you need the working..

just cross multiply 2-3sint with r.. replace rsint as y and r as sqrt(x^2 + y^2) and rearrange to get only the squareroot term on one side.. then square both sides.. and rearrange the terms..

Edited by Aquibex
Link to comment
Share on other sites

4x^2 + 3y^2 + 36y - 36 = 0

if you need the working..

just cross multiply 2-3sint with r.. replace rsint as y and r as sqrt(x^2 + y^2) and rearrange to get only the squareroot term on one side.. then square both sides.. and rearrange the terms..

I notice one problem. If either side is being squared, that means that there cannot be a single y^1 unit.

2r - 3y = 6

2(sqrt(x^2 + y^2)) = 6 + 3y

4x^2 + 4y^2 = 36 + 9y^2

4x^2 - 5y^2 - 36 = 0 is what I ended with.

Though, curiously enough, I received another solution through a different step (the step)

2r - 3y = 6 (Squaring everything immediately after this step)

4x^2 + 4y^2 + 9y^2 = 36 (I suppose this could be squared, but then everything is + or - and there are too many combinations of answers)

4x^2 + 13y^2 - 36 = 0 is another answer I received. Because of the property of square roots, there can be multiple different answers, right? One in which -3y is added and one in which -3y is squared. Either way, I never received a y^1 anywhere, so that has me confused.

Link to comment
Share on other sites

hey sorry about the really late reply.. my net was down for the past couple of days.. it seems i made a mistake as well.. here is the correct solution.. and you will get y^1.. the square of 6-3y becomes 38 - 36y + 9y^2.. putting an image for ur ref..

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...