Question

Find the length and foot of the perpendicular from the point (1,1,2) to the plane r.(2i-2j+4k) +5=0?

Answer 1

length =[ 2(1)-2(1)+4(2) +5]/√(4+4+16)

=(2-2+8+5)/√24

=13/√24

=13/(2√6)