Answer the following with reference to the point that represents 2 on the number line.
a. (i) State the meaning of the principle that every real number corresponds to exactly one point on a straight line and every point on that line corresponds to exactly one real number.
b. (ii) Point O represents 0 and point A represents 1 on the number line. From A, a segment AB of length 1 unit is drawn perpendicular to the line. The end B is joined to O. Explain clearly why the point P where OB meets the number line corresponds to 2.
c. (iii) Show that 2 cannot be expressed in the form qp where p and q are integers, q=0.
d. (iv) Write 2 correct to four decimal places.