Graphing-Adding Ordinates - Questions
Question 5
30611
i) On the same axes, sketch the curves \(y = \cos x,\, y = -\cos\dfrac{x}{2},\,\text{ and } y = \cos x - \cos\dfrac{x}{2}\), for \(-\pi \leq x \leq \pi\).
ii) From your graph, determine the number of values of \(x\) in the interval \(-\pi \leq x \leq\pi\) for which \(\cos x - \cos \dfrac{x}{2} = -1\).
iii) For what values of the constant \(K\) does \(\cos x - \cos\dfrac{x}{2} = K\) have exactly two solutions in the interval \(-\pi \leq x \leq \pi\)?