Identities of Halved Angles

Practice Questions

Trigonometry › Identities of Halved Angles

Questions

7

1

Find $\sin 2\theta$ if $\cos \theta = \frac{4}{5}$ and $\frac{3\pi}{2}<\theta<2\pi$ .

2

Find the exact value of $\sin 15^{\circ}$ using an appropriate half-angle identity.

3

Which of the following best represents $2cos^2(2\theta)$ ?

4

What is the amplitude of ?

5

If $cos(45^{\circ})=\frac{\sqrt{2}}{2}$ , then calculate $cos(22.5^{\circ})$ .

6

What is $\cos(\frac{5\pi}{12})$ ?

7

What is $\tan(15)$ , given that $\sin(30)$ and $\cos(30)$ are well defined values?

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