Finding Relation Between x and y

CAT 2000 Slot 1 · QA · Medium · Algebra

Given the following table of values for xx and yy:

xx123456
yy4814223244

In the above table, for suitably chosen constants aa, bb, and cc, which one of the following best describes the relation between yy and xx?

  1. A.

    y=a+bxy = a + bx

  2. B.

    y=a+bx+cx2y = a + bx + cx^2

  3. C.

    y=ea+bxy = e^{a + bx}

  4. D.

    None of these

Answer

B

Explanation

The second differences of yy are constant: 1st differences: 4,6,8,10,124, 6, 8, 10, 12 2nd differences: 2,2,2,22, 2, 2, 2 Since the second difference is constant, yy is a quadratic function of xx of the form y=a+bx+cx2y = a + bx + cx^2.

Practise this under exam conditions

Sign in to solve it with a live timer, the on-screen CAT calculator, and streak and accuracy tracking across every question you attempt.

Solve in the workspace