# Thread: parametrics question

1. ## parametrics question

Hi,

Stuck on this question:
convert x=tanx-sinx and y=tanx+sinx to cartesian form.

Thanks!  Reply With Quote

2. ## Re: parametrics question  Reply With Quote

3. ## Re: parametrics question Originally Posted by integral95 Umm if you try expanding and simplifying don't you get 0=0 which is saying we havent found a catesian relation?  Reply With Quote

4. ## Re: parametrics question Originally Posted by mathsbrain Umm if you try expanding and simplifying don't you get 0=0 which is saying we havent found a catesian relation?
True that, you should change tan^2 to sin^2/cos^2 then simplify to get

Then sub the equations from my 2nd line.  Reply With Quote

5. ## Re: parametrics question

Here's another solution:

i.e.

It's also clear to see solving this equation with gives the point just as it would for the parametric form. Therefore this is a valid conversion.

The graph of this equation is quite interesting.  Reply With Quote