Someone please explain these!

The angle between two planes is defined as the angle between their normals. Determine the angle theta between 0 and 90 degrees between the given planes.

a) 2x+3y-z+9 = 0 and x+2y+4 = 0

------------------------------------------

If the positive z-axiz points up, show that the line x=0, y=t, z=2t is parallel to and below the plane 2x-10y+5z-1 = 0.

-----------------------------------------
Find an equation for the set of points P(x,y,z) that are equidistant from the points A(1,2,3) and B(4,0,1)

1 answer

Love these kind of questions.

1. normals are (2,3,-1) and (1,2,0)

a∙b = │a││b│cosß

2+6+0 = (√14)(√5)cosß

cosß=8/√70

ß will be the angle between the normals, can you take it from here?

2. The line has direction (0,1,2) and the plane has a normal of (2,-10,5)

take the dot product.
If the normal is perpendicular to the line, shouldn't the line be paralle to the plane?

3. vector AB = (3,-2,-2)
this would be a normal to the plane, so the equation of the plane is

3x - 2y - 2z = C

Shouldn't this plane pass through the midpoint of AB ??

I am sure you can take it from there.
Similar Questions
  1. Someone please explain these!The angle between two planes is defined as the angle between their normals. Determine the angle
    1. answers icon 3 answers
  2. Someone please explain these!The angle between two planes is defined as the angle between their normals. Determine the angle
    1. answers icon 1 answer
    1. answers icon 0 answers
    1. answers icon 1 answer
more similar questions