MHB On desmos how do you plot y=3x as a polar equation

[karush]

Derive $y=3x$ as a polar equation and plot it.

?

 

[MarkFL]

You don't need technology here...what do you get when you make the following substitutions:

$$x=r\cos(\theta)$$

$$y=r\sin(\theta)$$

 

[karush]

View attachment 5340$$y=3x
\implies r\sin\left({x}\right)=3r\cos\left({x}\right)$$
$$\tan\left({x}\right)=3$$
no plot??

 

[karush]

I don't think thre is polar equation for a line that goes through the origin since there is no radius

 

[MarkFL]

I don't think thre is polar equation for a line that goes through the origin since there is no radius

The equation is simply:

$$\tan(\theta)=3$$

 

[topsquark]

I don't think thre is polar equation for a line that goes through the origin since there is no radius

Can you graph the line x = 4? There's no y here.

-Dan

 

[karush]

Can you graph the line x = 4? There's no y here.

-Dan

Yes but that is not a polar equation

And $\tan\left({\theta}\right)=3$ does not plot on desmos

 

[topsquark]

Yes but that is not a polar equation

And $\tan\left({\theta}\right)=3$ does not plot on desmos

Sorry. I don't know how I missed that...the desmos thing.

-Dan