Question

Find the distance from the point (-5, 5, 0) to the plane -5x+y-5z=5

Answer 1

find the unit Normal, find any point in the plane, find the vector from the point in the plane to the point you are given. Dot that vector with the unit Normal.

Answer 2

how do i find a point in the plane?

Answer 3

anyone will do.

Answer 4

i didnt get it right when i used (1,15,1)?

Answer 5

it'll work. But for your sake pick a simpler one. (-1,0, 0) looks pretty easy.

Answer 6

its not working?

Answer 7

you using the unit normal?

Answer 8

unit normal or just normal?

Answer 9

unit normal

Answer 10

still not working?

Answer 11

Proj (A sub B) remember? we're finding the projection of the random vector we made onto the normal... the length of that result is the distance from point to plane. Look up the projection formula if you're hazy on it....

Answer 12

Show steps if you like... I can't tell what is going right or wrong from 'still not working'

Answer 13

ok unit vector = <-5/sqrt(51),1/sqrt(51),-5/sqrt(51)> and projected onto <-4,5,0> (got from (-5,5,0) and (-1,0,0)

Answer 14

looks ok.

Answer 15

it says answer is wrong

Answer 16

25/sqrt(51) is wrong?

Answer 17

thats correct what did i do wrong

Answer 18

I got the same answer with @Algebraic!

Answer 19

how are you entering the answer? how are you supposed to be entering the answer?

Answer 20

as anything, its webworks

Answer 21

so 3.5 or something?

Answer 22

yeah or as 25/sqrt(51) it will take either answer

Answer 23

sure you're answering the right problem? and the values you gave are correct?

Answer 24

well your answer was correct i got a different answer somehow and got it wrong, ill go back through my work and figure it out

Answer 25

k.