Answer
$sin\theta=-\frac{2\sqrt 5}{5}, cos\theta=\frac{\sqrt 5}{5}, cot\theta=-\frac{1}{2}, sec\theta=\sqrt 5, csc\theta=-\frac{\sqrt 5}{2}$
Work Step by Step
Step 1. As $\theta$ is in quadrant IV, we know the signs of other functions.
Step 2. Form a right triangle with sides $x=1, y=2, r=\sqrt 5$
Step 3. We can find $sin\theta=-\frac{2\sqrt 5}{5}, cos\theta=\frac{\sqrt 5}{5}, cot\theta=-\frac{1}{2}, sec\theta=\sqrt 5, csc\theta=-\frac{\sqrt 5}{2}$
