Question 1
Which of the following is the correct identity for $\cos^2 \theta$?
Question 2
What is the double-angle identity for $\cos(2\theta)$?
Question 3
If $\sin \theta = \frac{1}{2}$, what is the value of $\cos(90^\circ - \theta)$?
Question 4
Which of the following is the correct identity for $\tan(\theta + \phi)$?
Question 5
What is the value of $\sin(2\theta)$ if $\sin \theta = \frac{1}{2}$?
