Reflecting vector i-3j+2k across line i-k

[gipc]

Find the reflection v' of v=i-3j+2k around the line i-k

how can I do that? I am extremely rusty with math these days;

 

[LCKurtz]

Call i-k = W. I would calculate the vector projection of V on W, call it V_p. Then the reflected vector is 2V_p-V. Draw a little triangle/parallelogram and you will see it.