Question

The terminal side of 0 is in quadrant IV and sin0 =

Answer 1

SOLUTION

Using Pythagorean theorem, it follows

$\begin{gathered} x^2+12^2=13^2 \\ x^2=13^2-12^2 \\ x^2=169-144 \\ x^2=25 \\ x=5 \end{gathered}$

Using the cosine rule it follows:

$\cos\theta=\frac{5}{13}$