If x is a number such that –2 ≤ x ≤ 2 which of the following

If you know how to plot graphs, this is very straight forward, most of the expressions are very simple to plot.

In case you want to do algebraically, here are a couple of simple rules you need to know:
(a) For linear expressions, the maxima or minima will always be at the extreme ends of a range
(b) For quadratic expressions, the maxima or minima will always either be the extreme end of a range of the global max/min of the function


3x – 1 : At ends, value is 5 and -7
x2 + 1 : At ends, value is 5 and global min value is at x=0, where it is 1
3 – x : At ends, value is 1, 5
x – 3 : At ends, value is -5,-1
x2– x : At ends, value is 2,6. Global min value is at x=0.5, where it is -0.25

(Its easy to tell what the global min for these simple quadratic functions is knowing where there roots are, it is half way between the roots)

Clearly, answer is A