Consider the functions p(x)=2x+1, q(x)=x2 and r(x)=3x, defined for x≥0.
a. (i) Without performing any numerical substitutions, explain which of the three functions grows the fastest as x becomes very large.
b. (ii) Draw rough sketches of the graphs of p, q and r on the same set of axes for 0≤x≤5. Label each graph clearly.
c. (iii) Using your sketches, identify an interval of x within 0≤x≤5 where q(x) exceeds both p(x) and r(x). Explain your observation.