Question

Use the unit circle to find cot 225°

Answer 1

Answer:

$\cot 225\degree=1$

Step-by-step explanation:

We want to use the unit circle to find the value of $\cot 225\degree$.

Note that $225\degree$ is in the third quadrant.

This makes an angle of $45\degree$  with the positive x-axis.

$\cot 225\degree=\frac{\cos225\degree}{\sin225\degree}$

$\cot 225\degree=\frac{-\cos45\degree}{-\sin45\degree}$

On the unit circle;

$\cos 45\degree=\sin 45\degree=\frac{\sqrt{2} }{2}$

$\cot 225\degree=\frac{-\frac{\sqrt{2}}{2}}{-\frac{\sqrt{2}}{2}}$

$\cot 225\degree=1$