Finding equation normal to a plane and certain point

In summary, to find the equation of a line that is normal to the plane $x + 2y + 3z = 12$ and passes through the point $(4,6,8)$, we use the formula $l(t)=a+tb$, where $a$ is the point on the line and $b$ is the direction vector. In this case, the direction vector is $(1,2,3)$ and the point on the line is $(4,6,8)$. Therefore, the equation of the line is $l(t)=(4,6,8)+t(1,2,3)$.
  • #1
brunette15
58
0
For the following question I am given a plane: x + 2y + 3z = 12. I want to find the equation of a line normal to the plane and going through the point (4,6,8). I am trying to use the formula N . (r - r0) = 0 however seem to be getting the incorrect answer :(
 
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  • #2
The line equation that passes through $a$ and is parallel to $b$ is $l(t)=a+tb$.

From the equation of the plane $x + 2y + 3z = 12$, we have that a normal vector to the plane is $(1,2,3)$.

We are looking for a line that is normal to the plane, so parallel to the vector $(1,2,3)$ and passes through the point $(4,6,8)$.

Can you find now the line equation?
 
  • #3
evinda said:
The line equation that passes through $a$ and is parallel to $b$ is $l(t)=a+tb$.

From the equation of the plane $x + 2y + 3z = 12$, we have that a normal vector to the plane is $(1,2,3)$.

We are looking for a line that is normal to the plane, so parallel to the vector $(1,2,3)$ and passes through the point $(4,6,8)$.

Can you find now the line equation?

Thankyou so much I was able to figure it out from there :)
 

1. What is a normal vector?

A normal vector is a vector that is perpendicular, or at a 90 degree angle, to a given surface or plane. In other words, it is a vector that is perpendicular to all vectors in a given plane.

2. How do you find the equation of a plane with a given normal vector and point?

To find the equation of a plane with a given normal vector and point, you can use the formula Ax + By + Cz = D, where A, B, and C are the components of the normal vector and x, y, and z are the coordinates of the point. The value of D can be found by plugging in the values of x, y, and z from the given point into the equation.

3. What is the significance of finding the equation of a plane?

Finding the equation of a plane allows us to understand the relationship between different points and vectors in 3D space. It also helps us to determine the orientation of the plane and its distance from the origin.

4. Can you find the equation of a plane with only two points?

No, to find the equation of a plane, you need at least three non-collinear points or a normal vector and a point. Having only two points is not enough information to determine a unique plane.

5. Is there more than one equation that can represent a given plane?

Yes, there are infinite equations that can represent a given plane. This is because planes are infinite in all directions and can be translated and rotated without changing the fundamental properties of the plane.

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