CAT 2000 — QA Question 2

In the above table, it can be seen that the values are taken at equal intervals. Also, the second differences i.e. values of ∆²y are constant and hence, the function is actually a polynomial of degree 2.

Thus, y = a + bx + cx² best describes the relation between y and x.

Hence, option (b).

Alternatively,

The relation between x and is not a line since $\frac{y_2-y_1}{x_2-x_1}$ is not a constant.

Also, e^a+bx will not be a whole number. Hence, by substituting values from the table, it can be checked that the relation is given by y = a + bx + cx².

Hence, option (b).