Let f(x)=x2.
a. (i) Choose any five non-zero values of x and tabulate the corresponding y-values. Show that for every chosen x, the same y occurs at −x.
b. (ii) Hence, prove that f(x) is an even function.
c. (iii) Using this property, justify why it is sufficient to plot the graph only for x≥0 and then reflect it to obtain the complete graph.
d. (iv) After drawing the full graph, estimate the set of all real numbers x for which y<3 and express your answer in interval notation.