MHB Convert Rectangular to Polar: Solving for $\theta$

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The discussion focuses on converting the rectangular equation y = 3x into polar coordinates, leading to the equation r*sin(θ) = 3r*cos(θ). This simplifies to tan(θ) = 3, resulting in θ = arctan(3). Users express frustration with Desmos not plotting θ as a function, although it can plot the polar equation r = -2 - 3sin(θ). Technical issues with using Desmos on an Android tablet are mentioned, suggesting that a laptop or desktop may provide a better experience.
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Covert to polar
$$y=3 x$$
I got... But it didn't plot on desmos... Can't show polar graph here?
$$r\sin\left({\theta}\right)=3r\cos\left({\theta}\right)$$
 
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karush said:
Covert to polar
$$y=3 x$$
I got... But it didn't plot on desmos... Can't show polar graph here?
$$r\sin\left({\theta}\right)=3r\cos\left({\theta}\right)$$

Simplifying further:
$$\sin(\theta)=3 \cos(\theta) \quad \implies \quad \tan(\theta)=3\quad\implies\quad \theta=\arctan(3).$$
Alas, it appears that Desmos cannot plot $\theta$ as a function of anything, yet.
 
OK, however desmos does plot

$$r=-2-3\sin\left({\theta}\right)$$

Although there is no way to put in $\theta$ on the drop down here
 
Hmm, let's see:

[desmos="-10,10,-10,10"]r=-2-3 sin(θ)[/desmos]

If you show the keyboard, then click the ABC on the lower left, you'll see a $\theta$ key. Interestingly, because I just typeset $\theta$ using the $\LaTeX$ code
Code:
$\theta$
I can copy that $\theta$ character and paste it into Desmos, and it understands it.
 
I tried but the keyboard would not appear hiting the icon off the interactive tab.

It may be because I am using a android tablet, I have a lot of problems with the finger zoom also, the taptalk ad enlarges so much that's all you can see
 
karush said:
I tried but the keyboard would not appear hiting the icon off the interactive tab.

It may be because I am using a android tablet, I have a lot of problems with the finger zoom also, the taptalk ad enlarges so much that's all you can see

Yeah, you're probably better off on a laptop or desktop. Still, we'd like our Tapatalk version to work ok, if possible.
 
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