Question

The scalar product of the vector i+j+k with unit vector along the sum of vectors 2i+4j-5k and ¥i+2j+3k is equal to one.Find the value of ¥.

Answer 1

on doing sum
$(2 + x)i + 6j - 2k$
on doing product
$2 + x + 6 - 2 = 0 \\ x + 6 = 0 \\ x = - 6$