Find the point(s) where the following plane and curve intersect:

2x+3y-9z=0

r(t)= <3cost, 3sint, cost> for [0,2pi]

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- Oct 25th 2012, 06:20 PMjessicadowningWhere does the plane intersect the curve?
Find the point(s) where the following plane and curve intersect:

2x+3y-9z=0

r(t)= <3cost, 3sint, cost> for [0,2pi] - Oct 25th 2012, 07:21 PMTheEmptySetRe: Where does the plane intersect the curve?
Just plug into the equation for the plane and solve for t!

$\displaystyle 6\cos(t)+9\sin(t)-9\cos(t)=0 \iff 9\sin(t)=3\cos(t) \iff \tan(t)=\frac{1}{3}$

Now taking the arctan of both sides gives

$\displaystyle t=\tan^{-1}\left( \frac{1}{3}\right)+\pi n, n \in \mathbb{Z}$

Now just restric n to get the solutions in the needed interval.