P1

May / June 2006

Question 11 (i)

Functions f and g are defined by

f : x → k − x for x ∈ R, where k is a constant,

g : x →9 / x + 2 for x ∈ R, x ≠ −2.

(i) Find the values of k for which the equation f(x) = g(x) has two equal roots and solve the equation f(x) = g(x) in these cases. [6]

I equated them and i got this

kx + 2k - x^2 - 2x = 9

x^2 + 2x - kx + 2k +9 = 0

x^2 + x(2 - k) + 2k + 9 = 0

form this point can some continue please try to include evry single step in solving.

Second question

P11

October / November 2009

The equation of a curve is y = 3 cos 2x. The equation of a line is x + 2y = pi. On the same diagram,

sketch the curve and the line for 0 ≤ x ≤ pi.

Ok i know how to draw 3 cos 2x, can some one draw and show x+ 2y = pi

Thanx in advance for your replies