Question

Find the equation of the plane through (1,2,-1) parallel to the plane 5x+y+7z=20.

Answer 1

wait sorry i think i over complicated it,
if its parallel then it will have the same normal

-->5x+y+7z = C
plug in given point to find C

Answer 2

So, c=0,
so the equation would be
--> 5x+y+7z=0?

Answer 3

yes

Answer 4

Thanks :)
So, all you have to do with these questions is plug in the points?

Answer 5

if the planes are parallel, then yes

Answer 6

How about perpendicular?

Answer 7

then you have to find a vector that is perpendicular to the normal by setting dot product =0

--> 5a+b+7c = 0
choose a,b,c such that it satisfies equation

then new plane is ax+by+cz = C
then plug in point

Answer 8

Oh Ok.

Answer 9

Thanks :)