In the diagram, the lower curve has equation \(y = \cos \theta\). The upper curve shows the result of applying a combination of transformations to \(y = \cos \theta\).
Find, in terms of a cosine function, the equation of the upper curve.
Functions f and g are such that
\(f(x) = 2 - 3 \sin 2x \quad \text{for} \; 0 \leq x \leq \pi,\)
\(g(x) = -2f(x) \quad \text{for} \; 0 \leq x \leq \pi.\)
(a) State the ranges of f and g.
The diagram below shows the graph of \(y = f(x)\).
(b) Sketch, on this diagram, the graph of \(y = g(x)\).
The function h is such that
\(h(x) = g(x + \pi) \quad \text{for} \; -\pi \leq x \leq 0.\)
(c) Describe fully a sequence of transformations that maps the curve \(y = f(x)\) on to \(y = h(x)\).
The diagram shows the graph of \(y = f(x)\), where \(f(x) = \frac{3}{2} \cos 2x + \frac{1}{2}\) for \(0 \leq x \leq \pi\).
(a) State the range of \(f\).
A function \(g\) is such that \(g(x) = f(x) + k\), where \(k\) is a positive constant. The x-axis is a tangent to the curve \(y = g(x)\).
(b) State the value of \(k\) and hence describe fully the transformation that maps the curve \(y = f(x)\) on to \(y = g(x)\).
(c) State the equation of the curve which is the reflection of \(y = f(x)\) in the x-axis. Give your answer in the form \(y = a \cos 2x + b\), where \(a\) and \(b\) are constants.