Diurnal motion is an astronomical term referring to the apparent daily motion of stars in "orbit" around the Earth. It is important to note that stars only appear to be orbiting the Earth. Such motion can be shown by time-exposure[?]photography. Some of the more circumpolar stars may appear to be motionless.
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If the discriminant is zero, then there is a repeated solution x, and this solution is real. (Geometrically, this means that the parabola described by the ...