Finding Line Equation Passing Through Point P0 & Parallel to Line

AI Thread Summary
To find the parametric equation of a line passing through point P0(1,-1,-3) and parallel to the line defined by (x+1)/1=(y+2)/4=(z-1)/0, the direction vector can be extracted as <1, 4, 0>. The parametric equations can then be formulated as x=2t+1, y=4t-1, z=-3. Understanding that any line parallel to a given line maintains the same directional coefficients is crucial. This approach simplifies deriving the equations needed for the problem.
lorik
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Homework Statement


The problem is pretty simple but I seem to be missing something essential .Write parametric equation of line which passes through point P0(1,-1,-3) and is parallel with line (x+1)/1=(y+2)/4=(z-1)/0


Homework Equations


solutions are x=2t+1 ,y=4t-1,z=-3


The Attempt at a Solution


I would really really appreciate if u could simply say the magic word because this looks really easy but yet troubling to my brain I think I am tired !
 
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lorik said:

Homework Statement


The problem is pretty simple but I seem to be missing something essential .Write parametric equation of line which passes through point P0(1,-1,-3) and is parallel with line (x+1)/1=(y+2)/4=(z-1)/0


Homework Equations


solutions are x=2t+1 ,y=4t-1,z=-3


The Attempt at a Solution


I would really really appreciate if u could simply say the magic word because this looks really easy but yet troubling to my brain I think I am tired !

If you know a point on a line and a vector parallel to the line, can you get the parametric equations for the line?

You can extract the coordinates of a vector from the symmetric equations (x+1)/1=(y+2)/4=(z-1)/0; namely <1, 4, 0>.

That should get you started.
 
lorik said:
is parallel with line (x+1)/1=(y+2)/4=(z-1)/0

What is the direction of this line?
 
Mark44 said:
If you know a point on a line and a vector parallel to the line, can you get the parametric equations for the line?

You can extract the coordinates of a vector from the symmetric equations (x+1)/1=(y+2)/4=(z-1)/0; namely <1, 4, 0>.

That should get you started.

And you're Awesome !
 
In general, any line parallel to
\frac{x- x_0}{A}= \frac{y- y_0}{B}= \frac{z- z_0}{C}

and passing through the point (x_0, y_0, z_0) is of the form
\frac{x-x_1}{A}= \frac{y- y_1}{B}= \frac{z- z_1}{C}

That is, it is precisely the numbers A, B, C that determine the direction.
 
I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
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