1. A coin is biased so that the probability that is shows heads on any one throw is p. The coin is thrown twice.

The probability that the coin shows heads exactly once is (8/25).

Show that 25p^2 - 25p + 4 = 0.

2. http://img220.imageshack.us/img220/4699/fofxir0.png

This diagram shows part of the graph of y = f(x).

(a) Find f(3).

(b) Solve f(x) = 6.

(c) Find ff(1).

(d) Find an estimate for the gradient of the curve at the point where x = -1.

(e) The equation f(x) = k, where k is a number, has 3 solutions between x = -2 and x = 4.

Complete the inequalities which k must satisfy.

..... < k < .....