Solving Cartesian Equation: r= 9 cosθ

  • Thread starter Thread starter knv
  • Start date Start date
  • Tags Tags
    Cartesian
Click For Summary

Homework Help Overview

The discussion revolves around converting the polar equation r = 9 cosθ into its Cartesian form. Participants are exploring the relationship between polar and Cartesian coordinates, specifically focusing on the implications of the equation in a Cartesian context.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the conversion process, referencing the relationships rcosθ = x and cosθ = x/r. There are attempts to derive the Cartesian equation, with one participant expressing confusion over the correctness of their result.

Discussion Status

Some participants have provided feedback on the derived equations, suggesting that the original attempts may be correct but not in the expected format for submission. There is an acknowledgment of the challenges posed by software requirements for homework submissions.

Contextual Notes

Participants mention issues related to the format required by the online homework system, indicating that the simplification of results may be a factor in the perceived correctness of their answers.

knv
Messages
17
Reaction score
0
1. Find a Cartesian equation to represent the curve r = 9 cosθ



2. I know that rcosθ= x and cos θ= x/r



3. I got (x-9/2)^2 +y^2 = (9/2)^2 but its coming up wrong when I put it into our online homework. Can anyone help me?
 
Physics news on Phys.org
hi knv! :smile:

(try using the X2 button just above the Reply box :wink:)
knv said:
1. Find a Cartesian equation to represent the curve r = 9 cosθ
I got (x-9/2)2 +y2 = (9/2)^2

how?? :confused:

anyway, just multiply by r …

r2 = 9rcosθ :smile:​
 
knv said:
1. Find a Cartesian equation to represent the curve r = 9 cosθ



2. I know that rcosθ= x and cos θ= x/r



3. I got (x-9/2)^2 +y^2 = (9/2)^2 but its coming up wrong when I put it into our online homework. Can anyone help me?

Your result looks correct to me. It probably has something to do with how you "simplify" it before you type in the answer. Maybe something simple like writing the right side as 81/4?
 
the answer was more simple than I thought.

x2+y2=9x


Thanks!
 
knv said:
the answer was more simple than I thought.

x2+y2=9x


Thanks!

So your original answer was correct, just not in the form the software wanted.
 
yes. I always get things wrong just because its not in the form the software wanted. Miss when we could turn homework in on paper haha
 

Similar threads

Convert the polar equation to the Cartesian equation
  • · Replies 1 ·
Replies
1
Views
2K
Convert the Cartesian equation to the polar equation
  • · Replies 1 ·
Replies
1
Views
2K
Express exp(3+Pi*i) in Cartesian Form
  • · Replies 3 ·
Replies
3
Views
2K
Double integrals: cartesian to polar coordinates
  • · Replies 3 ·
Replies
3
Views
2K
Is this the correct general solution of the given PDE?
  • · Replies 12 ·
Replies
12
Views
1K
Show proof of point C in the given problem that involves Polar equation
  • · Replies 3 ·
Replies
3
Views
1K
Setting the limits of an integral
  • · Replies 3 ·
Replies
3
Views
2K
How to know which variable comes first in the Jacobian?
  • · Replies 2 ·
Replies
2
Views
2K
Change integration limits for cylindrical to cartesian coord
  • · Replies 1 ·
Replies
1
Views
2K
Graph the Cartesian equation: x=4t^2, y=2t
  • · Replies 2 ·
Replies
2
Views
3K