CAPE Pure Mathematics Unit 1 · May/June 2010 · Paper 1 · Question Q32

Which of the following real functions is discontinuous?

1. (A)f(x) = \frac{x}{x^2 + 1}
2. (B)f(x) = \frac{4}{(x + 1)^2}
3. (C)f(x) = 3 - x^2
4. (D)f(x) = \sqrt{x^2 + 9}