Cylindrical coordinates of line through a point?

whig4life

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Sep 24, 2012
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Use cylindrical coordinates to describe the line through the point (1,1,0) and parallel to the z-axis.
 
Use cylindrical coordinates to describe the line through the point (1,1,0) and parallel to the z-axis.
What have you tried? Without seeing your work we don't know where you are stuck.
Have you sketched what a line parallel to the z-axis looks like? If you pick some point along the line, how do r and theta change?
 
Use cylindrical coordinates to describe the line through the point (1,1,0) and parallel to the z-axis.

Hint:

How would you describe the point (1,1) in polar co-ordinate?


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Please share your work with us indicating exactly where you are stuck - so that we may know where to begin to help you.
 
Sorry for keeping this to myself, it was purely an error of ommission--

The z-axis is (0,0,1) while the cylindrical coordinates are (√2, ∏/4, z)

Now, is the solution in the form of r=r0+tv? Or am I completely lost? (haha)
 
Sorry for keeping this to myself, it was purely an error of ommission--

The z-axis is (0,0,1) while the cylindrical coordinates are (√2, ∏/4, z)

Now, is the solution in the form of r=r0+tv? Or am I completely lost? (haha)
Yes, the line is (√2, ∏/4, z).

Not sure what the 2nd part of the question is.
In parametric form, r(t) = √2, theta(t) = ∏/4, and z(t) = t
In vector form, r0 = (√2, ∏/4, 0) and r = r0 + (0,0,1)t
 
Yes, the line is (√2, ∏/4, z).

Not sure what the 2nd part of the question is.
In parametric form, r(t) = √2, theta(t) = ∏/4, and z(t) = t
In vector form, r0 = (√2, ∏/4, 0) and r = r0 + (0,0,1)t


I believe the second part is asking what conditions r,θ, and z need to satisfy.
 
So am I correct in stating that the answer is: r= (√2, ∏/4, 0) + (0,0,1)t ?
 
So am I correct in stating that the answer is: r= (√2, ∏/4, 0) + (0,0,1)t ?
Yes - write the r in bold to show it is a vector, and NOT the same as the rho or r component in the cylindrical coordinates. In the same vector sense, r0 = (√2, ∏/4, 0) and v = (0,0,1).
 
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