Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

I have to find an equation for a plane normal to the vector $\vec{r(t)} = \langle e^{t}sin(\frac{\pi t}{2}),e^{t}cos(\frac{\pi t}{2}),t^{2}\rangle$ when $t=1$. I know I have to find the derivative and then plug in the value for t such that $\vec{r'(1)}$, then use each coordinate of the point with this vector to determine an equation. But since I don't have a point I don't know how to proceed. What is the best way to tackle this?

share|improve this question
    
You need to find the plane passing through $r(1)$ that is perpendicular to the vector $r'(1)$. I am guessing that you meant $r$, not $r'$ above? –  copper.hat May 25 '12 at 6:50
    
oops. yes. sorry about that. –  Dylan May 25 '12 at 7:01
    
I am still not clear on how to find this since you simply restated the question. All of the examples in the book give a known point to start with. Thanks. –  Dylan May 25 '12 at 7:04
1  
I'm not sure what point you are looking for. The point $r(1) = (e,0,1)$ is on the plane. –  copper.hat May 25 '12 at 7:10
add comment

1 Answer

up vote 2 down vote accepted

The equation is $r'(1) \centerdot ((x,y,z) - r(1)) = 0 $

share|improve this answer
    
I see. r(1) itself is the point. That makes sense now. –  Dylan May 25 '12 at 7:12
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.