Review question

# An exact value for $\sin 15^{\circ}$... Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R7050

## Question

1. Without using tables, show for $\theta=15^\circ$ that $\sin\theta=\dfrac{\sqrt{6}-\sqrt{2}}{4}$, and find the values of $\cos\theta$ and $\tan\theta$.

2. In the triangle $ABC$, $B$ is a right angle and the other angles are such that if a point $E$ on $BC$ and between $B$ and $C$ is chosen so that $BE=BA$, then there is a point $D$ on $AC$ and between $A$ and $C$ such that $AD=DE=EC$. Find the ratio of $DC$ to $AB$.