## Trigonometry (10th Edition)

1. Use the cotangent to get the values of x and y x=1 and y=2 2. Use x, y and distance formula to find the r $r=\sqrt{1^{2}+2^{2}}=\sqrt 5$ 3. Let's find cos and sin: $\cos\theta=\frac{1}{\sqrt 5}$ $\sin\theta=\frac{2}{\sqrt 5}$ 4. We can see from step (3) cosine and sine are not 1 and 2. When we divide them the root-5's cancel, then we get cotangent 1/2.