Hi,

Here is my problem: Show that the curve with the parametric equation $\displaystyle x=t \cos (t)$, $\displaystyle y=t \sin (t)$, $\displaystyle z=t$ is contained in the cone $\displaystyle z^2=x^2+y^2$.

My attempt : I don't really know how to show this. However I've showed that $\displaystyle x$, $\displaystyle y$ and $\displaystyle z$ satisfy the equation of the cone. Does that mean it forms it? Does that mean that the parametric curve is in the cone? What does this exactly mean?

Thanks in advance.