Trigonometry - Trigonometric Graphs and Parameters

Trigonometry - Trigonometric Graphs and Parameters

TGM Original Questions

The function \(f\) is defined, for \(0 \le x \le 2\pi\), by \(f(x) = -4\cos 2x + 1\).

  1. Sketch the graph of \(y = f(x)\) for \(0 \le x \le 2\pi\).
  2. By sketching a proper straight line on the same diagram, find the number of solutions to the equation \(2\pi \cos 2x - x + \pi = 0\) for \(0 \le x \le 2\pi\).
  3. Find the range of the value of \(k\) for which the equation \(-4\cos 2x + 1 - k = 0\) has more than two unique solutions for \(0 \le x \le 2\pi\).

Video Solution:

Video Solution

Video solution locked

A free account saves your progress; this video needs a course plan.

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs a course plan.

Answer:(i) See sketch. (ii) Draw \(y=3-\dfrac{2x}{\pi}\): 4 solutions. (iii) \(-3\le k<5\).

Need help? Join our A-Maths tuition classes.

Learn more