It is the horizontal line that is perpendicular to the y axis at the point of origin
Which point is not located on the xaxis or the yaxis of a coordinate grid?Read more:Which_point_is_not_located_on_the_xaxis_or_the_yaxis_of_a_coordinate_grid
A typical human male has an X and a Y sex chromosome pair.
It is called the ordinate.
.... then your graph is inverted.
xy + xy = 2xy
xy - xy = 0
XY
It is an expression in the form of: xy+7
We use y_y axes
The answer depends on whether xy are commutative numbers or operators in a permutation group.
During a typical power plant startup, all components of the power plant are started slowly. The turbine is first rolled at a slow rpm. Then the rpm is increased gradually to a point where it can match the frequency of the grid. At this point, the turbine can be synchronized with the grid and start outputting electricity into the grid.
You should find the answer on the ordnance survey website: http://www.ordnancesurvey.co.uk/oswebsite/gi/nationalgrid/nghelp1.html In essence the first two digits of X and Y correspond to a grid of alphabetical references, giving you the first two letters of the BNG. Hope this helps.