The origin lies on which side of the graph x + y < 5?
Left of line
Right of line
Above the line
Data inadequate
From the graph drawn below we find that the origin lies on the left side of the graph.
A square with each side equal to a lies above the x-axis and has one vertex at the origin. One of the sides passing through the origin makes an angle α(0<α<π4) with the positive direction of the x-axis. Equation of a diagonal of the square is