If vector a=(x,2,-6) and vector b=(1,-1,-6) and a=b find the value of x?

1 Answer
Apr 1, 2018

#x = sqrt(2)i#

Explanation:

The formula for the magnitude of a vector can be used to solve for #x#:

vector magnitude: #sqrt(x^{2}+y^{2}+z^{2})#

Since the magnitude of #vec{a}# is equal to the magnitude of #vec{b}#:
#a = b#
#sqrt(x^{2}+(2)^{2}+(-6)^{2}) = sqrt((1)^{2}+(-1)^{2}+(-6)^{2})#
#x^{2}+(2)^{2}+(-6)^{2} = (1)^{2}+(-1)^{2}+(-6)^{2}#
#x^{2}+4+36 = 1+1+36#
#x^{2}+40 = 38#
#x^{2} = -2#
#x = sqrt(-2)#
#x = sqrt(2)i#