# Thread: some algebra and distance formula

1. ## some algebra and distance formula

P = (4, -3, 7) Q = (-2, 5, 1) R= (3, 0, k)

PR=QR

What is K……

using normal algebra i got a slightly off answer.... arrggg

2. Originally Posted by stones44
P = (4, -3, 7) Q = (-2, 5, 1) R= (3, 0, k)

PR=QR

What is K……

using normal algebra i got a slightly off answer.... arrggg
we want $(4 - 3)^2 + (-3 - 0)^2 + (7 - k)^2 = (-2 - 3)^2 + (5 - 0)^2 + (1 - k)^2$

was that what you did? there should be much trouble working these out, the squares will cancel so you need only deal with a linear equation

3. yeah i got it...i was just off 1 number..that messed it ALL up