WORKED SOLUTION
4) The equation of a curve is
y = 3 cos 2x + 7 sin x + 2.
Find the x-coordinates of the stationary points in the interval 0 ≤ x ≤ pi. Give each answer correct to
3 significant figures.
8) The complex number w is defined by w = (22 + 4i)/(2
− i)^2.
(i) Without using a calculator, show that w = 2 + 4i.
(ii) It is given that p is a real number such that (pi/4) ≤ arg(w
+ p) ≤ (3pi/4). Find the set of possible values
of p.
(iii) The complex conjugate of w is denoted by w*. The complex numbers w and w* are represented
in an Argand diagram by the points S and T respectively. Find, in the form |z-a| = k, the
equation of the circle passing through S, T and the origin.