Proving Parallelism of Line and Plane in 2x-y+4z=81 and x-2/3=y-3/2=z-1

  • Thread starter Thread starter fiziksfun
  • Start date Start date
  • Tags Tags
    Lines Planes
fiziksfun
Messages
77
Reaction score
0

Homework Statement





show that the plane 2x - y + 4z = 81

never intersects the line

\frac{x-2}{3}=\frac{y-3}{2}=z-1



Homework Equations



??


The Attempt at a Solution



I wanted to show that the line and the plane were parallel. So the unit vector for the line would be 3i + 3j + 1k
RIGHT?
Then I get confused how to show this is parallel to the plane
Planes don't have unit vectors do they ?
The vector normal to the plane i suppose is 2i + -j + 4z

So if the two were parallel a dot b would be = 0
but this doesn't work ... help
 
Physics news on Phys.org
I think the unit vector of the line is 3i+2j+k. But that doesn't change anything, the direction vector and the normal vector still aren't perpendicular. That can only mean that the line and the plane must intersect. There is probably a typo in the problem.
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
Back
Top