In three-dimensional Euclidean space a coordinate system x′a is related to the Cartesian coordinates xa by
x1=x′1+x′2,x2=x′1−x′2,x3=2x′1x′2+x′3.
Describe the coordinate surfaces in the primed system. Obtain the metric functions gab′ in the primed system and hence show that these coordinates are not orthogonal. Calculate the volume element dV in the primed coordinate system.